I'm new to this forum, but not forums in general. About a year ago I purchased a Pratt and Whitney 10" engine lathe for 200 bucks. When I went to look at it, it was in pieces in a trailer inside the guys shop. Originally he was asking around 800, and I looked it over, everything felt tight and it came with a bunch of extra goodies. I told him I couldn't realistically give him his asking price without seeing it running. He responded with "make me an offer". I asked him to not be offended, and said I could do 200. He immediately said sold! And we loaded it up.
Anyways, the lathe uses 5p collets, which I can't find anywhere (currently there's a 4 pack on eBay, other then these I haven't seen anything in the last year). I have the draw bar, and one 1/2" collet. Should I just keep waiting and looking? Or is it possible to convert to a different collet?
The other thing is the spindle threads. They are 2.75"X8tpi! I've never seen a backing plate in this size, and I only have 1, which is on my 4 jaw. But I purchased a 3 jaw, and would prefer to not have to swap plates Everytime. Has anybody seen these or have a lead? I know I can turn one on the lathe, which brings us to my next question....
My experience has been on Southend's with quick change boxes. My lathe did luckily come with all of the change gears, but without a threading dial, I am completely clueless as to how to cut threads on this thing? Any pointers?
It also came with some tooling that I'm unfamiliar with, but I believe some is unusable with my lathe. I'll try to post some more pictures later and see if y'all can identify them.

Thanks for any help,