Brand is correct Don!
The SA-9100 however is from 1973/4 and looks like this:
View attachment 39583
This amplifier is from the late 1980s.
Ain't no good at keeping track of all the new-fangled stuff, mate. It all looks sooo tantalizingly familiar, and 1980 is the time I was actually in the audio business, need to cogitate... I don't think we carried Pioneer though I saw plenty of it. They made some huge high-powered (200 W+/ch) receivers around then IIRC (*). Several products used the long coupling shaft for the input switch to put it on a board at the back right at the inputs.
LIke this one: http://www.classicaudio.com/value/pio/SX1980.html