[MOTORHEAD]

Have you removed the air cleaner top to verify fuel delivery ?
You say the plugs were wet, Did you pull them all and dry them ?
You said there is spark at every plug, but is it there at the right time? Ck with timing light.
Did you ck the dist cap for moisture, carbon tracking, center contact worn/ missing?
Last time mine would't start, found cap full of moisture.
I seem to recall a BDR we had with the same problem and symptoms. Finally just threw in a new dist module and that cured it.
You can have spark when you check it externally, no compression pressure to overcome, but cranking the engine, the cyl pressure may kill the spark. If the module doesn't do the job, you'll have the spare MSD part that everyone should carry !