RevGQ:

Irwin will tell you anything to keep from having to take responsibility, but the fact is, the seller has a responsibility to provide a "marketable" product. In plain english that means that the parts of the airplane that are assembled by the factory have to be adequate and safe for normal use.

If there was no light ply under the servo screws, that airplane was not safe when you got it. You do not have a legal responsibility to recheck the factory's work. (Although in hindsight, it might have been a good idea.) GSP is responsible not only for the loss of the plane, but also for any damages caused by the unsafe airplane. (Like your engine and radio, anything the airplane hit when it crashed, and maybe even the time you spent putting it together.)

Sue him in small claims court, you have an excellent case.

Jim