George,
I have a great-great grandfather that applied for a Confederate pension from Florida, and was initially turned down because the "witness" to his service on his pension application had been a deserter, unbeknownst to my ancestor. He later reapplied using a different witness and was ultimately approved.
You cited the UDC criteria for its membership. The SCV eligibility includes the following statement: "Membership in the Sons of Confederate Veterans is open to all male descendants of any veteran who served honorably in the Confederate armed forces."
Best Regards,
Greg