So, yeah, I farked the pattern for a the HT7550 regulator on a bunch of boards, swapped Gnd and Vout.
This is what it is supposed to be....
This is what I put on the boards
The specs of this reg are not critical in the slightest, so if I can find one with the pin out I used it would solve the problem... but try as I might I can't find any SOT-89, or even SOT-23 (I could make it fit easily I think) that match my screwed up pin out.
So, anyway, I figure it's worth posting to see if anybody knows of one, don't care if it's a name-brand or some dark chinese part, I'm sure I'm not the first person to make this particular cock up.