The one your looking at is the lighter weight one, about 350 lbs, the one I got is the model #590 and is about 650 lbs. The one Moleman has shows 700 lbs on HF's site.
It's just a little smaller then the one I got, 4" stroke compared to 5". The table is a little smaller, 20"x6" mine is 28"x8". They both have 12 speeds, yours has a little slower low speed but the high speed is about the same.
OK that's just some of the minor differences, other then that they are almost the same, I don't know what they left out to get it 300 lbs lighter. You will need a solid & heavy bench/table to mount it to, being that light it might shimmy or hop if you get to hard on a cut.
As for cutting receivers, I think it would but for ones like milled receivers it would take a while and everything would have to be done with light cuts. But then again your not a business trying to pump them out as fast as you can, you want it for the hobby and save some money not paying the businessman his fees.
In my opinion, if you can get it for around $200 (you have to judge on it's condition and how hard it was used) it would be a decent starter/small project mill, if they want more then that you'll have to think about it hard.
But that's my $.02, it might be worth more but I'd think a mill almost 30 years old won't be in excellent condition.
And you have to think about the vise, if it looks like a nice quality vice that might make a difference in the price you think about, a good vise can run $100-200 easy. If it looks basic or low end, just think of it as a part of the mill and don't give it any value, a cheap vice is just that "cheap" and you can got one of those yourself.
If you decide to get it and there's no manual, let me know and I'll try to scan mine for you. But the manual isn't very good, the belt settings and exploded views are about the only really useful info in it.
Hope my rambling was useful