in the old days there were no PA systems as we have today and fender amps were used for vocals as well. in fact. iirc, that is why there is mixing resistors at the inputs so multiple instruments or mics could be plugged into them.
that box is more like a fenders NORMAL channel, like the alembic F2B, but without a mid control like the normal channel of a deluxe reverb etc..
to be more akin to a jerry pre that third gain stage really excites things, which is missing. reverb is also a must for jerry.
Disclaimer: I make and sell Buffers. I also sometimes Modify, Build and sell preamps and amplifiers. My opinions are not intended to be sales pitches. I am a one man shop and prefer to spend time with my wife and family, i work full time on call and love to spend my spare time doing other things. I only make, modify or build things for those that seek them.