RE: BVM F-4 CG
Not sure why you chaps are bothered about this. I used to fly my F4 with the CG at 12 1/4 inches along the LE, flew fine, then BV sent me a note saying it flew better at 12 3/4 inches, moved mine back flew even better, think it improves landings too.
I just measured mine by standing at the front of the model and lifted it on two fingers pointing towards each other at the 12 3/4 point marked on pieces of masking tape. Simple quick, works ! Indicating the CG along the LE seems to me the simplest way of doing it and I now use exactly that technique on all swept wing jets, inc. 45 pounds of Hawk !
Regards,
David Gladwin.