49ers Font Question

[MReamer66]

Recently came across an old 49ers jersey with a January 1990 tag. It has a different font on the six than what was used in the 1990 season (photo attached). The jersey is banged up and has stains on the shoulders and sleeves. Here is where things really get interesting, when doing my research I cam across a picture from the 49ers training camp that had this font but it wasn't used in the 88 or 89 season. I know at that time the 49ers were Wilson then went to Russell then back to Wilson. Does anyone know if there was different font used in training camp or preseason or early models of 1990 prior to the season? Thanks, sorry for the headache.