I'm guessing you meant S6006L which are Teccor 6A 600v isolated tab SCR (the 6060 is a 60A device and is definitely not in a TO220 package!) and the D6020L is a 600v 20A isolated tab diode also from Teccor. Shouldnt be too hard to work out the circuit, its going to be a full-wave half controlled bridge (2 diodes, 2 SCR arranged as a bridge rectifier) the third diode is a snubber across the motor. What other parts are there on the board?