300 Hurst broadcast sheet – velour interior?…Help please

I found build sheet under velour seat, which seemed to be untouched (but who knows after 50 yrs). Why do I have velour/leather seats when every other 300 Hurst has all leather seats? Previous owner didn't know but said doors used to be velour fabric as well but were changed because original cloth fell apart.

1) Why does my broadcast sheet state "38 Special Order" or "Imp set up"? (see pics) I'm guessing this is special to the interior only, since VIN and Fender tag already show its a...

300 Hurst broadcast sheet - velour interior?...Help please