The 65 was available in two configurations. The regular model, and shorter barrelled and rarely seen, LP65 Short.

-The 80 is very similar to the regular 65, more available adjustment on the trigger.

-The 80 uses a series of barrel weights rather than the 65's barrel shroud, so a little more flexible in that respect.

-The rounded action of the 65 gives way to a more angular frame on the 80 which is reminiscent of that seen on FWB 150/300 rifles forward of the breech area.

-The grip angle was slightly revised on the 80.

So the differences aren't huge, the LP80 is perhaps slightly more desireable but fewer were made so finding a 65 may be easier.