So I take it that at some point the gun sight and its reflector (for the Zero) has been modelled to a different size than originally?
I don't think so. Yesterday, I copied successfully your A6M2 gunsight to all A6M3 non-stock folders and realized there are differences in PoV between various sub-models; in addition, I use
SAS PoV Mod which could put some way back pilot's PoV in cockpit.
Does this apply to the J2M as well, which the game originally assigned the same sight? How about the Army planes?
J2M looks as follows:
for comparison, here follows same reticle with stock gunsight:
All Army planes are OK for me.
4.08 didn't have an A6M3 folder; did 4.09?
No, it doesn't, they are the non-stock A6M3 that I listed previously, which do have their own folders.
All in, I think it's mainly a matter of oversized reticle (in respect of the real one, which looks all inside the reflector glass and even the dimmer), complicated by some difference in PoV.