I just bought an 82 FXB. I actually responded to an ad about an 82 FXS but to my surprise it was a Sturgis. It is a numbers match but the tank, seat, handlebars/controls, and primary cover are not original.
They made thousands. If someone wanted one for that purpose it would have to be 100% original, paint, parts, decals etc. Not rebuilt, not modified. Just ride it and don't worry about resale.
1,833 FXB (Sturgis) models for 1982. Obviously worth more completely stock and unmolested, but if ya get it at the right price, getting it back to stock condition is always cool