Yes Campagnolo dropouts on the Grand Record and above frames. I would not question Chas' detailed analysis: if hes says this is a 73-74 GR then that it is, and a great frame you got there! Worth re-painting it and outfitting with some better brakes (cause even tho many are non-original the remaining stuff is not bad but go over everything). Congrats on joining the Moto GR gang (I have one in black/red with nearly all original kit).