Sorry for that. Had to go out with the wife and a half a post wasn't worth leaving.
It's the same gun (as the 500) but the AB had a really nice scalloped bolt and lifter. It was a serious attempt at a hunting gun, nice blue, real walnut with grip cap etc....and some stores sold them with hunting scenes engraved into the receivers.
Check it to be sure it's a two bar receiver/bolt slide, but other than that, they're interchangeable (with the 500). The bolt and lifter will probably want to be replaced, though....they're just too pretty for a knockaround gun.
r