Not sure what a JSA Certificate is but the manufacturer of this issue was not United States Postal Service as stated on the certificate. This stamp was issued by the United States Post Office Department and manufactured by the United States Bureau of Engraving & Printing.
Ok guys, by reputable I mean an actual authentication company, not self certifying. JSA is at all of the big sports memorabilia shows and their opinions are accepted. The founder was an expertizer for PSA/DNA.
You can find fault with anybody if you wish. Google Philatelic Foundation certificate scandal.