[ouidjat]

I know nothing about the way those planes got such paintings; but for sure many of II./JG 52 planes presented the same "rusty" aspect judging from the available pictures.

I think, whatever, there is something to do with the fact they have been brought from another (others?) unit.
The most common feature being the large patch under code number.
And since not all did bear a chevron it's another reason to consider Lipfert's plane out of this business - It's a possibility but not a strong one.
Better; II./JG 52 used small numbers and - of course - larger ones have been painted over hence the said large patches.

For the rest, as I said, I don't know.

Regards, Franck.