Check the clutch release arm for a crack. A crack may not be apparent with the clutch engaged, but will open right up when the clutch is depressed.
Jim
It may be a dirt particle or a small flake of rust that has made its way through the fuel bowl and is partially blocking the bottom of the main jet causing the engine to run lean.
I second Joe K's recommendation above. Powder Coating Alternatives did 5 wheels for me back in 2009. Sand blast, undercoated each with a 25% zinc rich powder coat and finished them in gloss black for $443.75. The car is driven every week when I can and the wheels still look like they were done...
Consider using a "brakelighter" by J&L Enterprises (see sticky above). They are unobtrusive and mount inside the rear window with suction cups. They act like a third brake light as well as directional lights. The guy behind you will see a high mounted light way before he sees bumper mounted...
Talk with your plumber. Mine uses a hand held with a flexible wand. An extension can be added to increase viewing distance. I don't know if it has memory capability to be able to be downloaded to a PC. Most major tool manufacturers have similar versions.
The back plate has post production brush holders, I can't tell from your photo if the end plate is cast iron or aluminum. The wiring can be easily changed to install a Model A type stud terminal with the ground wire terminated inside the generator case. The result would be a correct looking...
It sounds like an air leak. Check for manifold to block tightness, carb to manifold tightness. Condition of gaskets in both areas. Crack in carb mounting flange / manifold. If you have a vacuum tapping on the manifold, remove the wiper connection or plug and temporarily install a vacuum gauge...