I assume you're referring to the 3AJ type twin lamp fairing, tank and low level guard, like the bike on the right here. I think it could be made to fit a later bike, but with significant additional brackets requiring welding on to carry both tank and fairing. You'd need to fit the seat too, in order to get the interface right...and the side panels and tail piece would then be wrong! Also there would be a wasted void under the tank where the 1VJ/3AJ air box lives. Basically it would be a right pain, and look terrible! Oh, and good bits like tanks are getting pretty hard to find these days.
If that's the look you really want, why not chop in your 600E for a complete 3AJ? Difficult to find a good one, but worth looking for. It the engine is clapped, yours will drop in.
Or you could consider using the readily available big Acerbis tank for the XT 600E and a higher aftermarket fairing - the one fitted to the XL Honda in the pic cost about 40 quid and bolted on easily around a standard rectangular headlight.
Me? I still think the standard 1VJ - on the left - is where it's at!