This is one of the "ultra-linear" (UL) Super Reverb models which began being produced after 1977 or so. The transformers are different in these. The power transformer has a higher B+ voltage, along with the solid state rectifier, supposedly squeezing 70 watts out of the two 6L6GC power tubes, and the output transformer has different taps as well. I think that despite the flak these sometimes take, they are capable of good tone when running properly, which I hope this video will demonstrate.
Lots of guys become fixated on making an amp something it is not. I do not recommend "Blackfacing" these ultralinear Fenders. I think they should be serviced and enjoyed for what they are. The tone from every UL Fender I've played through has been very good and very versatile.
CLICK HERE for an earlier 1975 Super Reverb demo: https://www.youtube.com/watch?v=ESx4VAW0OcE&list=UU2DDLacv42cfgT7Urv9n3dg&index=67