MXR Dyna Comp, pots date to 1980 so 80-81 for the compressor. There is an MXR labelled rubber pot cover for the Output knob, you can turn that knob with your foot. No LED or power supply socket, pre Dunlop.
"MXR INNOVATIONS" cast into the bottom plate. I gently pulled the foam up to photograph the circuit board, then put the foam back, it stabilizes the circuit board. A 9v battery that is still lively is included.
I carefully cleaned the jacks.
This works fine and has that MXR Dyna Comp tone in spades - chimey and smooth.
Hefty and solidly built, no wonder that it's still alive and kicking at 42+ years old!!!
Local cash only, no shipping