Here is a selection of some of those questions and my effort to answer. If you think you can improve the answer please email me.
Question: How can I know the engine size of my car: 2,0 or 2,3 litre?
Answer: According to Ford of Cologne, the admited tire sizes for the OSI 20m TS (beside the original 185 SR 15 Pirelli Cinturato mounted in 5,5J x 15 Fergat wheels) are:
The 195 x 15 size is not admited in the OSI 20m TS.
The Geneva prototype used Borrani RW 4016 5,5 x 15 wheels 42 type mounting (62,5 mm diameter with 75 splines) with three eared spinners but you can also use the 52 type (73 mm diameter with 88 splines) because these wheels were used in Jaguar and are easyer and cheaper to find (The wheel type designation refers to the maximum size of the outer bearing in millimetres which can be used with that hub).The easyer solution is to find 5 stud bolt-on hub adapters with a pitch circle diameter of 112 mm, the same as Mercedes (the pitch circle diameter is an imaginary circle that passes in the centre of the holes or bolts). Depending on the adapters, it is very likely that you will have to shorten the studs and use thinner wheel nuts.
I will be back later on this issue with drawings and measures and even torque tightening values.
Answer: Yes, with minor changes. Up to chassis number 01878 the exhaust system is the same of the standard 1964-1967 Taunus 20m (P5) with only one resonator chamber and you only need to cut 90 mm to the muffler exit pipe (2 in the picture bellow). From this number up is the same as the Taunus 20m TS (P7 based) exhaust system with two resonator chambers and there is no difference between the 2,0 and 2,3 litre models. You must check the picture to see where to cut (three segments).
Answer: Well, it was a nightmare to find weatherstrips. OSI had special tooling to place the mouldings on the rubber but there is a good way to do it without special tools: Find a good safe stand for the windshield, mount the weatherstrip on it and just then apply the moulding. Finally apply the windshield complete with weatherstrip and moulding to the car. Do not try any other order. Anyway, this serves for both front and rear weatherstrips.
If you cannot find weatherstrips I can help you with accurate dimensions so you can find someone to extrude rubber for you or I can even find you quality weatherstrips.
10 front and rear rubbers ready to be cleaned up. contact me if you need one.