Accel plugs are actually Nippon-Denso "U-groove" disasters, absolutely junk.
No need for holding a point set open to adjust the other point on Accel dual-point distributors. To properly set them, conncet your dwell meter as normal, to the neg side of coil, start engine, disconnect the one wire from distributor to coil that has connector, set the point for the other wire to 26 degrees. Connect the connector back up, set second point to give 33 degrees dwell overall, done. Set timing, go.