Official difference between the G-10 and K-4 windscreen??

[von Lutz]

Attachment 1290
I think the difference is not G or K but whehter the aircaft has an MG 151/20 or MK-108. The former has the ammo bin in the left wing while the latter had it directly above the cannon. This reguired access to the top of the MK 108 ammo bin just forward of the windscreen. As seen in the attached foto of the PoF Bf 109G-10, the steel welded cover in front of the windscreen was required to be able to access the top of the ammo bin. Also the MK 108 elect. panel lying horizontal above the ammo bin opening could be rotated 90 degrees toward the windscreen. Both G-10s restored by Evergreen have this same style cover.

Sorry you were unable to get a response from PoF, but the Valle museum crew consists of only a few people how have every little time to answer inquiries.

Hope this answers some of your questions.