You asked if this amp was anything special. I think any Fisher amp from the 50s is something special. The #60 chassis was from the 1957 model year. The series 61 consolette was from the 1958 model year. Console/chassis mismatches seemed to have been fairly commonplace among Fisher's consolettes during the 50s and probably came from the factory like that.
The schematic for the #51 chassis (which is the 1958 version of your chassis w/o the tuner) shows one phono input and two aux inputs. Any aux input lead should run directly to the front section of the selector switch. The phono input leads should feed pin 3 of the 6SC7 through a capacitor with another lead running to the rear section of the selector switch. However, I believe that any lead running from an input jack to pin 5 of the 6SC7 would be bypassing the phono stage since that is the plate of 2nd triode in the 6SC7, hence its output. Maybe someone wanted another line level input.