Re: Seized Engine
I had this happen to me more than I want to admit when I started with the China Girls. I got lazy and used a small earth-magnet on the end of a string to retrieve ring pieces and needle-bearing pieces (they're magnetic), but this won't help with any aluminum chunks if there's port-skirt damage. There's also no guarantee that you'll get everything out since stuff can get stuck in the bearings and other hiding places. I have even filled the crankcase with gas and churned it with the flywheel...then dumped the fluid in hopes of clearing out any loose debris. It worked twice, failed once. I haven't had any problems with my build for a LOOOOONG time now, so I haven't had to even pull the head off in a few months. What you SHOULD do, and what I did the last time I had an issue is split the case and clean it out with premix. This is a great way to familiarize yourself with the engine, and will also give you the opportunity to make sure it's assembled properly; you may find that some things weren't installed as carefully as you'd like when the engine was born in China.
So, sorry to be pessimistic, but you should expect that since your engine seized, the top-end is damaged; almost invariably in your situation, the loose ring piece is drawn up one of the the transfer-ports and gets jammed beween the piston-head and the cylinder wall ruining rings and the jug (although I had the opposite occur, and the cylinder wall was damaged BELOW the combustion-chamber). I have in desperation and cheapness replaced only the rings after a failure. If the cylinder gouging is minor, you can actually get by although your compression will be effected, you'll just need to dremel away some of the raised areas on the piston/jug, and even out the ring-lands. Even a really badly damaged piston can sometimes be resurrected if the pins are still good. In any case, you'll need to remove that head to see what's up, AND you may need to force it off.