[Heathkit] SK-201 Soft Key Module Question..

[KBØNLY]

Trying to build a SK-201 since Harbach isn't taking orders at this time.  I just about got it figured out except for one thing.  The schematic isn't really clear on the 4n33 connections.

Pin 1 goes to the junction of D3 and R3, and pin 2 goes to ground, pin 3 is not used.

On the other side which goes to which?  Pin 6 is the Base, Pin 5 is the Collector, and Pin 4 is the Emitter.  It looks like pin 4 should be ground and pin 5 should go to the junction of R1, R2, and Q1?  That would mean Pin 6, the Base, is not used correct?

73,

Scott