Undoubtedly that's a tape from e real German fighter's guncamera, not from La-7
... I saw a lot of latter in 176 GIAP photo-album, they are different, and the tape is US-made, not Zeiss...
Hehe, I think that Kozhedub's 'kills' are only the rumor because all such events were fixed in Soviet documents. I saw few detailed documents describing 866 IAP Yaks combat with P-38 on 7.11.44 with 'victories' and own losses, but there isn't a single word about those misterious Mustangs...