Makes no difference where the parts are, they will be shipped, if available from another warehouse.
When you say low compression, what is the problem, valves, head, rings, pistons? I can run a check tomorrow, if I can get the time, to see what is available.
Then again, Black Tuesday is just around the corner, and who knows, I might not be a GM employee come Wed.
After working very closely with the Saturn assistance center in TN, as an engineering consultant (one of a three), not sure how customer assistance would check for parts. Most of them have no idea where the piston goes.
If mine was out for more than two weeks, I would hit them up for a complete new engine, head or short block, depending on what is actually wrong.