Finally gave up and took the car to a real carb expert. He found multiple problems caused by the initial "expert" that tweaked my carbs, including at least one blown power valve, damaged needle/seats, and incorrect float adjustments. Both carbs were taken off, and new parts installed and adjusted. Car now starts right up, and runs fine. I only lost about four weeks of driving time
- Never again.
Lesson learned: Never let another touch your car, unless you are absolutely sure he is qualified.
Thanks to all who submitted suggestions. It seems that there were just too many issues to overcome, requiring the carbs to be stripped back down to start at zero again to ensure all was correct.