Parts from eBay will be faster than overseas, but what is the problem? There's a dowdy seal on each of the three pipes, one on each end. Those blow constantly on mine. Your spare parts kit that came with it should have a couple spares. You can buy more stateside if you need.
I blew the top piston. The compressor simply locked up, so that doesn't seem to be your problem. I had new piston tops (the top of the piston screws in, so I just ordered that part) and replaced it. There are videos on YouTube showing all the steps, but TAKE PICTURES OF THE REED VALVE. I downloaded the only video I could find on how to put it back together. https://www.youtube.com/watch?v=24sGXYkd4NY
The worst part is that it took two months for the top of the piston to show up, then when I tried to reassemble it, the gasket had shrunk and I had to order another oil gasket and was down for another 2 months. If you need to remove the front of the compressor, might want to just order another gasket unless you are good at making your own.
If it's just a seal, you can start the compressor, let it build a little pressure. Hold your hand to the sides of each of the metal pipes. If you can feel air escaping, it's probably one of those dowdy seals. I've replaced so many, I've got a system down. Though remember the metal pipes screw into aluminum blocks and are easily stripped. Use two open end wrenches to tighten the pipes on top of the dowdy seals.
And of course, if the repair will be over $75 or $100, just buy a new one and keep the old one for parts.
Good luck, they are very simple devices, but a real pain to work on.