761XL's had a hammer dampening bumper like a 1300 on the early self cocking systems as well as an oversize steel bolt knob.. Standard 760 was smooth bore. They also had Brass colored sideplates and rifleds barrels.
The 760XL was a later gun on the hammer drop design. At that point I think all the guns were rifled. They were also a lot cheaper made with lots of plastic. Not special. The 761 was.
You could fit a rifled 761 barrel(761-003) to a 760 and if you did not abuse the barrel with BB's it could be a real sleeper 760. Put together right these little plinkers can be insanely accurate with the 761 tube.
I don't have any left but I'd bet there are some out their squirreled away.
"NO GUNS WOULD BE A RIOT"