Many thanks for the wisdom you passed on to me. Based upon your recommendations I bought a new Consew 206rb-5 and a motor from Toldeo Industrial Sewing Machine. The motor has a 45mm drive pulley.
The large 6” pulley for the speed control has an A groove. I couldn’t source a 6” M groove pulley. The drive belt is from Harbor Freight. The smaller 2” speed control pulley has an M groove and came with a 15mm keyway hole. I drilled it out to 5/8” and tapped it for an allen screw. The shaft is 5/8”.
It can stroke at less than once per second.