She just died on me yesterday while driving and won't fire back up. I'm now trying to diagnose the problem.

The basics - 1951, 216, rebuilt carb, new 6v battery. Was running perfectly up until a month ago when it began hesitating, lean backfiring and stalling. Rebuilt carb installed and problem solved. Ran great until yesterday when she died and coasted to the shoulder.

The current issue - She turns over no problem, I can smell fuel and she puffs a bit occasionally like she's gonna fire up only to not and eventually backfire at the pipe. The starter rolls it with or without the coil wire just the same, so my guess is spark ... the occasional puff and/or backfire says its intermittent.
The plugs, points and cap are new and adjusted and the wires are new-ish so my guess is the coil. 6v coil ran on 8v for years by the previous owner, I'm guessing its just burnt up.

Also, The inside of the cap at the coil end of the wire that connects to the coil to the distributer is very oily and grimy. I replaced it with a new wire but it had no effect. ...still thinking bad coil.

Am I totally off base here or does this sound reasonable?