came form underneath the brake/cluch pedal assembly. It seems of lesser quality than the rest of the electronics. Aftermarket?

 

That's not a stock part.

 

Cruise control or alarm module,have seen them a looong time ago,can't remember which. Any wiring,switches(on clutch pedal) or a second throttle cable or linkage under hood. Siren? Neither was of best quality-didn't last long.
Alarms were a popular add on,these cars were stolen quite frequently. Did a lot of theft recovery repairs,was amazed how many were all but gutted and ins.co.paid for repairs. Made for steady work. All you needed to steal one was a pair of pliers to twist the key lock out of the door,hammer,screwdriver to start it.

 

I've seen aftermarket things like those over the years. Just removed an aftermarket alarm system for a customer recently and it had a small module similar to that. I wouldn't be afraid to remove it and forget about it.