I'm certain that all the dark colored G-10's were Erla produced but I don't think that the earlier G's in dark camo are from the same origin. I think they might be from recycled airframes from older aircraft, put together at a repairshop and given a quick dark camo to blend the parts in, not by Erla though.
Unique for these dark Erla G-10's is that there was NO RLM 76 on the entire fuselage, the dark colors went all around. The wings were mostly natural metal with only wooden parts painted RLM76. That is totally in line with the latest RLM instructions for camoflage issued during the war. I got to read up on it but as I recall, these instructions included that the two upper colors were to be applied in a cloudy pattern and be taken down the sides directly over natural metal. A good description of my interpretation of these aircraft actually.
Black 1 is a Bf109G-2 flown in the east by JG54 and repainted in their various greens.
EDIT: Rasmussen posted while I wrote so additionally, what's your take on the colors if not 83? What about the more traditionally camoflaged G-10's from Erla, do you believe them to have been 74/75 up to the end?
Cheers! / Anders