If Jeff replaced the rotor when he restored your distributor, I doubt that the rotor is the problem (he has about the only rotors that don't cause a problem). That said, it wouldn't hurt to try a different rotor (purchase it from Jeff so you get one that will last). If you are still running with points, then check the points gap AND try a new condenser. New condensers usually fail in the first few hours of installation if they are going to fail at all. Finally, you say that the distributor is in correctly - I am going to ask if you are certain that you got it in and set up with #1 cylinder at TDC on the compression stroke? Remember that the mark on the crankshaft pulley will line up with the timing pointer when the #1 cylinder is TDC on the compression stroke AND with the #4 cylinder at TDC on the compression stroke. Unless you checked which cylinder was on the compression stroke, you have a 50 - 50 chance of getting it wrong (or right).
Cheers,
Dave
http://homepages.donobi.net/sufuelpumps/