The extended deadline of 15 October is rapidly approaching and I already read of suggestions for GB8! By my reckoning, we have 8 completions and there's three biplane builds in progress:
Nils:
Stampe & Vertongen SV.4b
F_IV:
Mitsubishi F1M2
Glehn:
Antonov An-2 Colt (I am assuming the white one is now finished)
Happy to leave the GB6 folder open past the deadline to allow you to complete these. After all, I don't want anyone else joining me on the GB Shelf of Shame!

OTB ...
GB20 - AW.650-222 Argosy (MikroMir); GB22 - B-25J Mitchell (Academy-Minicraft); Non-GB - Pe-2 (Decapod 3D)