Dan,
Definitely not trash can fodder. Also not unusual for a motor that's been sitting. typical 2 stroke deposits plus moisture from the air plus some time will glue the rings into the grooves.
I would soak the pistons and rings in something like carb cleaner, or other good solvent to see if they will free up. Might need to soak for several days. Don't use anything water based if you have to let it sit for more than several hours, as water based stuff may cause more harm than good due to dissimilar metal corrosion. (cast iron and aluminum) Did that once, didn't turn out well!!
Eventually you should be able to wiggle the rings free gradually. Don't force or they'll break. That's not really a big problem, as 175 rings should be fairly easy to come by, and you may want to replace the rings anyway depending on how they look.
Once you get them freed up, you can use the sharp end of a ring as sort of a scraper to get the deposits out of the piston grooves. They make tools for this, but I've always used a ring end with good results.
If the rings and piston grooves clean up ok, and the rings are then free in the grooves, you can probably re-use them.
Good luck!
