If it's been setting, you may have a stuck ring. Have you checked the compression?

Have you turned the distributor one way or the other while cranking?
Have you verified TDC, and that the distributor is pointing at the right plug at the right time?

Are the spark plugs firing?
Are the plugs wet from NOT firing?
Have you tried a 12 volt battery on the starter ( if 6 volt ) to spin the engine much faster?