1. Lots of carbon/soot on the plugs (checked 2).
2. Idle transfer slot, as found: About .060 uncovered primary, completely covered on the secondary side.
As left: About .030 primary, completely covered secondary (no change made)
3. Idle mixture screws: As left: About 1 turn out, primary; about 1/2 turn out secondary.
Results were very encouraging but not 100%. Off-idle hesitation is much less severe, but still present. During the mixture screw adjustments, at no time did manifold vacuum improve when I (gently) tapped the accel pump lever. Adding fuel was always a detrimental effect. So it wants more air. I'm not finished tinkering with the idle mixture just yet (I'm going to try the technique advocated by Don Gould at
www.4secondsflat.com, which is very similar to the advice given here), but I 'm thinking about a small hole in the primary butterflies.
Thanks for all the suggestions and guidance, and please keep it coming.
CWizard