Just get their records from serving in the Confederacy. That’s what the 14th Amendment is about.
Of course you’re right. Since the last insurrectionist, the last confederate soldier, died in 1951, I think we’re ok. Unfortunately, for the libs, whatever crazy a** s*** one of them thinks up is immediately and permanently takes as Gospel by millions of their brain dead followers, so they’ll go to their graves still believing the January 6 fairy tale.