Thanks guys - I grabbed a loupe and found the part # for the female panel connector (it is amphenol) on the pack - a little googling got me the part # for the female cable connector...
... and viola! Eighty bucks! An extension cable is only $70. But an ebay search found some NOS parts for $20 (and no desoldering). A little more googling found a wealth of how-to's as well.
And yes John, I have no desire whatsoever to open a pack! I have a nice 1205 that uses an oddball AC cable which would be an easy swap to a more common one (I'm terrified of getting to a gig without that one crazy cable) but I'm not interested in even loosening a single screw on that thing (though on my old toggle-switch packs, you do have to tighten the ring-nuts on the switches from time to time - that's about as far as I'll go, just takes pliers externally...)
Mike, some guys mention putting liquid flux on the cups - is that necessary? The speedo is an 8-pin, but there are only 7 wires in the cable, I'm guessing one pin isn't used.
And yes, this would be a methodical job, as a crossed connector could have some bad consequences. I'm thinking it might be visually clear to plug the connectors together before soldering, so the correct wires would be "across" from each other vs. making notes of the pins. I score and record most of my commercial video edits, been a musician forever so I'm as anal as anyone about proper soldering - I do enjoy redoing guitar electronics and making custom snake cables. None of that stuff pushes this kind of voltage though.
Thanks again - John, I'll shoot you a PM regarding the solder - buy you a cocktail? Thanks again.
Speaking of tunes and guitars and solder - here's me, before the haircut that made my wife so happy: