And we have a winner!
It began with a pukka T370 chassis back in late 1974 when Alfa Romeo wanted to try their engine against Ferrari's;
Over 1975, Snellman designed the GH2 with the flat12 in mind, but MrE got the wind of it and Alfa changed their mind.
If you think about it, there's a bit of chassis cross-section resemblence between the GH2 and 1976 Brabham BT 45;
Your go and a vote!