Marvin Mims Jr. Signed Denver Broncos Jersey (JSA COA) Ex-Oklahoma Sooner W.R.Custom on field style jersey. Everything is sewn on, size Adult XL. Hand signed by Marvin Mims Jr. The autograph(s) includes an official James Spence Authentication (JSA) "Signature Debut" hologram and COA. "Signature Debut" is the autographed memorabilia equivalent to a rookie card. The JSA definition of a "Signature Debut" is as follows: "Any item that is autographed and received by JSA prior to the last game of the signer's official rookie season.