Things like this can be really frustrating, sometimes it is best to look for the simple things first.
If it runs real rich at idle and the idle screw adjustments don't work as they should, perhaps you should look at the float level.
Some of the early plastic floats can get 'gas-logged' so even with the proper float height settings they will sink a bit causing a high fuel level in the float bowl and the gas will overflow internally causing a rich condition.
You really can't tell if this has happened by looking at the float so I would suggest replacing the float and checking the float height settings before changing any adjustments or parts that came 'stock'.
If you should happen to have a brass float, check it for gas inside, they will leak too sometimes, it doesn't take much change in buoyancy to affect the float level.
Did you get your idle stop solenoid issue resolved?
Good luck,
Tim
