good looking mount Chuckk!
interesting puzzle non-fixie. suspect fork not original.
are dropouts pretend forged? recall seeing some 531 plain gauge falcons with these. had one such come through about forty some year back.
have a falcon hanging in the rack but cannot measure headplate holes for you as am ~700 km distant from it at present.
no doubt, the forum's falcon experts will be along momentarily to enlighten us...
looking forward to reading their observations.