Yes, you have right, there is only few left - i knew about seven 3Gd. I am a 3Gd fan, and have collected cars and parts for some times. And I restoring a 3Gd 1938. I will present the project later.
Manuals are a problem! I still not have a parts list, have only one for the civilian type. Some one have original manuals - that is for sure!
The production was 4297. The only 3Gd that is restored, and we have seen at the road is the one that Bjarne Fjeld in Norway had. Three or four are under restoration, one in Germany is nearly finished restored.
During the production Adler change the front, and some other construction, like the filling of petrol, which was on the left side in 1936 and leather at the right side.
Adler 3Gd front history: 1936: With cast aluminum grille with small network, and side louvre with many horizontal narrow lines. 1936-37: With the same grill but the side louvre are change. 1938: With horizontal grille bars and vertical side louvre. This front change is not done for the look, it was necessary because the engine need cooling!
The most of the war photos show this last design. The biggest production was in 1938-39.
The color give me some headache. Outside it is RAL7021, under that is camo and as a basic it is greygreen. And after some dismount, it was obvious that the hole vehicle have been greygreen. I will strip of the RAL7021 so I can see how the camo look like:) Also other 3Gd owners have found the same color.
Searching for missing parts, literature and knowledge about details have take time. Differential, headlights, K98 brackets, airfilter etc is some of the “problem” parts. At eBay I have bought a lot of photos, this has given me valuable information.
This is parts I still searching for. Riemann 190mm headlight .The lamp have a red indicator lamp at the top. Airfilter with flange Ø58 or 63mm And I still missing literature – have only the parts list for the civilian type – and manual for the service. D632/43 “Sonderausrüstung für Winterbetrieb” is a manual I need.
The K98 bracket for the rear seat was a long time a mystery, but one day I found a photo that give me an idée what I should look after! One part for the K98 bracket come from Russia, one part from a friend, and one part I found myself! Then it was complete. This brackets is the same as in the Mercedes 320WK.
I mention the differential, many of the vehicles have problem with this. The problem is the planet wheel that seems to have wrong hardening. I am not sure but it look like that, the sun wheel is always ok. May be some of you have other explanation for this problem.
In year 2000 I bought a 3gd wreck, and I hope the differential was usable. I have luck, this have a automatic locking! There was no particle in the oil so I think it is ok. I hope this locking have a good function, time will show