That orange terminal block was GM first attempt at a diagnostic connector. I have seen many cars around the same age with the same connector mounted in various places under the hood.
The tech terminal is mainly used for a tach connection. I have seen aftermarket cruise control setups that have a tach input.
Some of the things previous owners do baffle me. A Mickey Mouse repair made at the side of the road just to get home? Ok, I can definitely understand that. If it’s really stupid in a creative way, I might even congratulate you for a McGuyver worthy fix. However, the people who spend more time and money trying to half-ass thing than just fixing it the correct way really grind my gears!! Even more so when the temporary fix becomes permanent.