I have heard that US necks don't fit as well, but I'm still of the belief that it's a Skyline body. I wonder what had to be done to that neck (or the body) to make it fit.
I have a first run JO (signature headstock) that's a VVT, but that's not what flagged it for me. It's the body ferrules/bolts and the finish appearance. It screams Skyline.
And bridge.
