My observations. As for the light gray, that would be Spain as far as I know and not light gray. The earliest went over unpainted. The light gray could be L40/50 or RLM 02, not clear as photos distort. Also. some C/D? went in a single Dark Green and were perhaps repainted in Spain. The German Dark Green did not work well in Spain for camouflage and perhaps there was a lot of repainting. Note the Es that went to Spain, they seem to have a unique scheme of a light color with that distinctive use of black from the exhaust, down the fuselage and across the wing root. I have pictures of Es being repainted. They may have arrived in RLM 71 and been repainted in 02. I cannot think of another country that received a light colored 109.
As for the others I believe the use of a Dark Green (71?) was standard on export, e.g. Swiss, Yugoslav, Romanian, etc. Your reference to a few in Bulgaria in 70/71 is interesting. I have poor pictures of 4 and 7 and both seem to show a single green. Love to see better images.
This use of a single green for export may explain the number of 109 D and E in Luftwaffe service that appear to have a single green camouflage. It may be as war was immanent, export aircraft were held back for the Luftwaffe. This would be similar to the way the US held back aircraft intended for the UK and appear in Dark Green and Dark Earth, as opposed to Olive Drab for USAAC aircraft.
Glad to share pictures.
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