Be sure if you do get a 50mm that the mirror-up position works correctly. I bought one, didn't use it for a while, and when I did, discovered the mirror lockup did not work. If you want to buy mine, knowing that, I'd sell it for fifty bucks. It works properly in all other regards.
They don't list it as being a C (multicoated) lens, so ask.
They have a 100-200 zoom which is almost mint and is smooth - I've seen it and it's beautiful (I'd buy it if I didn't have primes in that range). They have the support bracket as well. Also note that the 360mm needs a support bracket so you don't bend the focus rails.