Amendment: I got it going and without a fuel leak. I feel like a magician. It runs REALLY well up top, a bit anemic off idle and cruising, no doubt because I bottomed out the fuel screw. I'll add a turn and try it out tomorrow. I'm pretty happy with it so far!

As far as the o-rings go, I found a plumber's #7 ring in a hard rubber that did the job. No problems yet!

Thanks for the advice and help. If nothing else, got gears turning!