This set will be easy to find. The only difference is the registered top speed. It is now 61km/h not as original 53km/h. So I can drive on motorways, but this is not my intention. In Germany there are "Kraftfahrstrassen", which can look like a normal road or sometimes like a motorway, but the minimum registered speed is 60km/h. Sometimes it is tricky if you are on a trip. If you have to bypass these roads it can be a long detour. The fine for misuse is only 15 Euro, but your insurance coverage is gone in case of an accident.
In the 60th the speed limit was 50km/h, thats why the Unimog 411 was registered with 53km/h.
regards,
Markus