The cards in the main set are numbered with leading zeroes and are not in a gold circle.
Sorry, I thought it was a six. Hard to see. Not sure what set it's from, but it's not from the set you linked.
-- Dan --
Note: Please see my profile for more info regarding trading (section updated 10/25/2023). I have added a large portion of my inventory to the site, and currently have trading turned off (details are in my profile). I have (finally) unearthed my 2 very large boxes of Star Company minor league sets and they are available (email for details).