Grading Question

[crwill19]

A newbie here to the forum and pretty new to cards. I have a 1980 Rickey Henderson (not the original owner) that looked like it had a shot at a 10, so I sent into to PSA for grading. It came back N5: Altered. Doing some research it seems it was probably in a screw-down holder at some point. Also, read putting in a cigar box can help, so I have done that for the past month or so. Anyway, looking to get it re-graded. The card itself has perfect centering and nothing noticeable corner or edge-wise. Under the naked eye, the surface looks good. Taking a closer look under magnifying glass can see a few surface blemishes.

I have sent a batch of 80s football to BGS. (I liked the idea of the .5 grades), most of those came back lower than I thought. I have also sent in a Dan Marino rookie to PSA, that looked the same (to the naked) eye as the Henderson, which came back as an 8.

I'm now kinda leaning toward SGC to send the Henderson and other 80s cards. Is SGC the best option for 80s cards....Just looking for any feedback...Thanks