Yep, the power came in at the rear on the main board. I just added a little jumper set with a male and female connector to tap into the power. I can restore the unit to the original configuration just by pulling my little harness out.
I did a little grinding on the ridges of the tender and now two of the battery packs appear to fit. I'll have to arrange two charging jacks (not going to try to charge them in series), to charge the packs one at a time. However, this should yield at least 2-3 hours of runtime at full voltage so every thing works. I had to replace the huge speaker with a little flat one, surprisingly, it sounds just as good as the big one, obviously that one wasn't top shelf.
