Young gun,
The "AVL" was a transitional engine that was used on some models for a few years to bridge the gap between the older (and original) design and the spankin' new "UCE" engines of all models since around 2010 (was it?). Your bike has got the good 'ol fashioned, been around for 60 or so years, cast iron barreled engine.
If real "vintage" as opposed to "retro" is what you were after you got the right bike. It gets a little confusing because for one thing, RE designates essentially the same models by different names according to which market they're being sold in and also using the word "classic" in the naming of the new B5,and G5 UCE bikes. This sight doesn't help matters much since the advent of the B5'sand G5's by using the word "classic" in the heading for topics related to the cast iron barreled bikes. Personally, I think that anytime you have to call something classic in it's name, you are simply calling attention to some fakery. But again I digress.
Back to the AVL's for a moment, if you see one quickly, they do bear a passing resemblance to the older engines but there is absolutely nothing that is interchangeable about them.
The "Sixty-5" was a styling exercise (around 2004, I think) that also introduced the (then) new 5 speed gear box. It was built on the same old fashioned chassis as their other iron barreled models and was mechanically identical to them more or less. I say more or less because over the years,RE was transitioning away from whitworth fasteners and going metric and also royally
screwing with the crank case breather in the name of emissions compliance. There was no pin striping on the tank or fenders and the forks had rubber gaiters. Otherwise they were pretty much the same bikes.
So to sum it up, when you buy spares like gaskets and oil filters, chains and sprockets and cables and such, you have an IRON BARREL (say it proudly!). NField Gear (our host) refers to them now as "Legacy" models. Hitchcock's has a handy window on each of their products that will tell you immediately if the item fits your bike.
Oh, and another cool thing, when someone admires your bike and asks where they might perhaps get one, you can then smile ruefully and say, "they don't make 'em anymore".
Chuck.