I would go back to gravity fuel. Pull the carb apart if it has been fed from the tank and make sure it is clean. "rig" a safe gravity can, or rig a small can into the fuel pump inlet. I would pump some through the pump, into a can to flush it clean
If you do have spark, you can check timing "on the starter" --best to pull plugs to ease the starter load If timing is on spec to the emissions sticker I would bump it advance at least 5*
Sounds like you are pretty checked out, ATF in the cylinders, etc. Run a compression check?
For spark, bear in mind that if you jumper the starter solenoid, that gives you a weaker spark, because the coil will be operating through the ballast, which is bypassed when twisting the key to start