To me, unknown EBAY motors are not worth the gamble. Just look at some of the "mechanics" we have here 
A crate motor I will buy though......
I personally love to build my own motors, but I leave the porting and other precision work to guys better qualified with more knowledge and experience than asscrasher 
Tear it down and see what you've got. Those <85 200X parts are sooooooo plentiful that I'd imagine for about 500% you could build a nice tight and fresh reliable motor with both new and used components.
F the shop, read up, ask questions and do it yourself. Shops are >85$ an hour and filled with 20yo "mechanics" that can't take the time to do a great job when the boss is all over them about the time.
All our government does is distract us while they steal from us, misspend our tax $ and ruin our country