Mk1 Midge Prices. 
Remember added components will probably cost more than they add to the car's value, but will probably increase the likelihood of a sale.
Basic street legal car with MOT, runs, reasonably reliable. No crash damage or significant chassis rust.
Poor                                     Middling                             Excellent
   £                                           £                                                  £
0                                           200                                           400
Paint job (or other finish, eg fabric, wickerwork, polished alloy.)
Wire Wheels. (Really rusty ones can detract, but they must have a MOT pass to count.)
£50 Bonus for every inch above 13" 
100                                         300                                           1000
100                                         200                                           400
Fabric Roof with working frame. Side screens and quarter lights.
Instrumentation, switches and dashboard, accuracy and appearance.
​0                                             100                                            200
Headlights, indicators and tail lights. Windscreen wipers and door handles. 
Style, quality and configuration.
0                                              50                                              100
Tonneau cover. Vital if you have no roof, useful if you do.
0                                              50                                              100
Quality of interior trim. Seats, carpet, lining. Driving comfort, wheel and pedal position.
0                                              50                                              200
Eccentricity. Touches of brilliant design / art / humour and other imponderables
-5                                                                                               300
Wiring loom, appearance of alternator / dynamo/ starter. Is the engine bay nice?
0                                              50                                             100
Extras. appropriate mirrors, period AA/RAC badges, Bonnet strap, External horns, Picnic basket, Removable hard roof. etc
Neatness of suspension system, quality of windscreen mountings, some extra chrome or polish.
0                                              50                                            200
0                                              50                                            100
Mudguards, wings and running-boards where applicable. Stylish or gawky?
0                                              50                                            100
Personally I would say that having JC Midge, Special, Moss or  Roadster on the logbook, or something similar that is obviously not a Triumph type as the make/model gets a 20% bonus.  A 'Q' plate might not look nice, but it does indicate the vehicle has been 'modified' and then examined. 
Larger engine (1300 or 1500). Overdrive,  and other drive-train bonuses.Electric fan.
0                                              100                                            200
Current Historic Vehicle status (tax exempt)
Non transferrable LLL NNN,  NNN LLL or variations on LL NNNN numberplate. 
'Cherished' or  transferrable ones can be worth hundreds or even thousands.
     This is a work in progress, the writer (and MOBC) take no responsibility for any connection with actual vehicular values or sale prices, or how much fun you are going to get.
     Nor for additional costs (money, marriage, reputation, street cred, barked knuckles), your level of happiness, the weather, government legislation, the state of the roads or what your wife, friends, police, girlfriend or children think. 
    Remember,  lost opportunities, childhood, wish fulfilment and straight outright stupidity are your own responsibility, if you really, really want it then offer more, but remember....... 
    Cars (and drivers) built before the speed limits were introduced are still liable to them, even if they can't reach them.
    I may be adjusting the figures to conform with other people's opinions, and haven't worked out any inflation factor. The current top figure is in excess of £6000. That would be a spectacular car, I think there are one or two. Yours? No comment.
    In the end the value of the car is quite small, by comparison with a modern vehicle. The main problem is that the market value of a Midge isn't really the value an owner builder puts on it, but the value the buyer will pay. If you can buy an 'agreed equal quality' one for the money from the insurance company, then it would be difficult to argue for more. The value to the builder in terms of memory, sentiment and affection is something that cannot be valued and therefore cannot be paid. You can imagine the cry, "I have put my heart and soul into this, it is worth at least ten million, squillion pounds." Only to be answered by a cold hearted accountant...but could you have sold it for that? My calculator is that cold hearted accountant. Personally I like the low prices. Higher prices based on the time taken, heartache, blood, sweat, WD40, and tears would be in the hundreds of thousands, but the insurance policy would reflect that. Like the Picasso, it would stay in the bank vault, loved perhaps, but un-driven. No, no and thrice no I tell you.... it is worth a Midge. no more, no less, the extra value is not in the car, it's in the builder, the driver, the owner. He or she retains that long after the car has gone.
    Next question. Does the Midge have a soul? I'll get back to you on that.
    Some Midge parts are purpose built. Dash-tops, radiator surround, petrol tank and windscreens are often used because they would be difficult to make at home and were available with the Mk1 plans. They save a lot of construction time and the need for skills like casting your own alloy radiator surround
   Midges are coach-built or hand-made so they are not Kit-cars, but there are some common components such as wire wheels, headlights and the aforementioned parts as new and second-hand, for estimated prices and possible suppliers try Midge bits.
   Obviously an unfinished Midge will lack an MOT, but can be in very good condition. This is usually owing to ill health, and the value has to be based on careful evaluation. In practical terms the V5c then becomes much more important, followed by the chassis. The rest can be roughly determined by any experienced motor driver as long as it can be driven a few hundred yards. 
   There will always be problems, so after a superficial examination I would keep a contingency fund of 10 to 20% for surprises. If the seller isn't the builder this is a useful and fair bargaining chip if used diplomatically, but I mean it to be an idea of how much more you might need to spend to get on the road.