1) "former glory"? Most raced-in-the-day historic cars that you see beeing trotted out recently, and all the "tribute/youngtimer cars" are completely OVER restored well past their "former glory"...juss sayin'
2a) Nothing on this car looks even interesting, let alone "correct", legit period-racer.
2b) Even the most basic early Gp 1 cars allowed more development than this one shows. Vented front (and rear) brakes appear to be the only deviations from a basic vanilla stock undercarriage (well, there is the rear pipe for quick lifting.) If these were Koepchen mods, 40 years later they've lost any intrinsic value
3) Is the paperwork more than just delivery papers that show it was shipped to Koepchen, and a few pages of servicing/inspection records? Can someone translate please?