Thanks,guys,,won't actually know what transformer until I get to see it in person.
But from the pics and info on the referred thread, assuming colors are correct..to change 16/8 to an 8/4, does this procedure sound right? :
-Disconnect yellow 16 ohm wire from speaker jack but leave the 16 ohm yellow lead from transformer connected to feedback loop.
-Move the white 8ohm wire over to terminal on speaker jack where the yellow 16 ohm had been removed.
-Move brown 4 ohm wire from its parked terminal, to speaker jack terminal that the white 8ohm had been removed.
Am I missing anything?