Fixed it. Turned out to be four things:
1. The point gap was off (.025 instead of .015)
2. The plugs were fouled and their gap was off - replaced with new
3. The mixture was too rich
4. The 12V
feed into the control box was chaffed and shorting (the real cause of the intermittant stalls.)
I also checked the plug wires for arching, etc. Everything else seemed to be fine. It's such a relief to go from backfirings, smoking, coughing to purring like a kitten with less than $5.00 invested.
Thanks to all that provided input.