That was a big issue with Dynamic cards, autos on base cards /inserts. Because some of the signatures, particularly those like the Captains were through the Dynamic Collectors Club, they just used base and sent an A4 letter as the COA.
There are plenty of good Joey cards but if you want an auto, you are unlikely to get one that has been authenticated under $900 with done over $1500.
He had autos in Dynamic 95 (Captain), 96 National Heroes, and 96 (Signature Gold Acetate). These are the only ones you will get under $500ea.
Joey then had on card autos in 01 Challenge (All Stars), 04 Authentic (Captain), 06 Invincible (Record Breaker), 13 Traders (Legends) and 18 Glory (Immortal
Signature).
Good luck with the chase. I have done lower end inserts and parallels of Joey available.