I was given a copy of an old synopsis of the RV-Ator 1980-1997.
This was very useful.

I learned of the MIL-R-46196(MI) riveting standard, and there a mention of a common error where builders used 0.063" angle instead of the required 0.125" for the aileron bellcrank bracket. Sure enough, the previous builder used 0.063" on my right wing.