J-par
i think your still at the question as to what is it. If you can find one that works.........then who cares!
But if you have to find a aftermarket one..... now you need to know what that generator does.
creates a AC or DC voltage? is it a variable voltage..............or is it a pulse generator like you see attached to a speedo cable at the transmission. Which my guess is, that is what it does......but now there are many different pulse generators(how many pulse per rev does your tach calibrated to.
When i went looking i found 8 and 16 pulse per rev units if that's what it need then there about 20 buck, and that's no big deal.
If you need a different pulse then, that...............all i found was testers/simulator that were hundreds of dollars..........