Those appear to be 45ACP magazines. They're currently going for over $100 each. The loader is also for 45ACP mags. It looks like you have two extra bolts also, which means maybe the one in the rifle is for 45ACP and the full size spare is for 9mm. The smaller bolt (under the barrel) appears to be a 22cal conversion. If you don't have any 9mm magazines, it may mean whoever owned it was primarily using it in 45ACP, but that's just a guess. Nice haul. If you're interested in selling it, I'm sure someone on this board would be willing to take it off your hands at a fair price. Otherwise, I'd say enjoy a day at the range with it.