You have already pointed out the frame, which is a dead give-away, as well as the non PRV crankcases, but apart from the half-width hubs and front numberplate style front mudguards, just about every other item on that bike seems later, post 1988 forks, 90's tank with big filler cap, Mikarb carburettor, modern battery box, etc...
It is possible to start with a genuine early frame and build up a bike with all recent parts, and I did see quite a nice Indian restoration where this was the case, but the seller's story about this being a 1963 Redditch export doesn't hold water.
Just to confuse matters some Indian suppliers are now selling frames modified with the older style gearbox mounts. Have a look here, first picture on the second row.
http://royalenfieldzone.com/vintage_parts.asp
A.
