McIntosh MC2155 mystery switches

You solved the mystery Detective Jameswei! And, I have no defense, as they ARE mentioned in the owner's manual as you suggested, but not pictured there, or labeled on amp. One is to turn on/off Power Guard beep, and the other to speed or slow Power Guard countdown.
Thanks, I have no clue how I missed that.

These are probably system test switches for the Power Guard circuit. The Power Guard circuit is supposed to prevent amplifier clipping by automatically turning down the input volume when it senses the amp approaching clipping volumes. There's some descriptions of it if you Google.

If you have the owner's manual, there may be a discussion of Power Guard and the system test function for it.