Long shot, but are your distributer gears perhaps stripped? I'm not 100% sure, but if you bump the starter with the cap off, you should see the rotor [that is the rotor, right?] spinning.
Have you been able to verify the coil is giving spark to the distributor? I'm pretty sure if you pull the wire off the distributor [that comes from the coil] and crank the engine over, you should see spark in there..