Thanks Peter.

Yes, the +KM was a typo (which I've fixed), I did mean +FM. I'd just been looking through "Battle of Britain Then & Now" (p.613) and discovered that Nacke also apparently flew "M8+KM" (W.Nr.3603) on 31 August 1940.

I'm unsure about dates when Borchers became StaKa of 5./ZG76 (Wikipedia suggests Autumn 1940). However, to confuse the matter, Jan J. Safarik's website lists all of Borchers' victories from 1940 as 4./ZG76 (according to this, his last victory of 1940 was on 11 September). On the other hand, Wikipedia suggests Borchers was in 5./ZG76 from 1 September 1939 until his Staffel became 8./NJG3 in Autumn 1941.

Christer Bergstom in his Battle of Britain book conveniently gets around this by saying Borchers was in II./ZG76.