1969 Hazard/Emergency Switch Wiring Question

[bxd]

Hey all,

I recently purchased the correct (1969 MY only) hazard switch for my 911. -At some point in my cars' life, a previous owner replaced the original rubber-knobbed, 6-pin, pull switch with a later red plastic, 7-pin, push-button model. After removing the incorrect 7-pin switch and looking at the harness wires, one major thing became immediately apparent... the 6-pin switch has pins for 6 of the 7 wires (obviously), but not the brown ground wire. The 6-pin switch has pins for 15, 30, 49, 49a, L and R, but not pin 31 (which is the ground pin):



Looking at the factory wiring schematic, the ground (31) seems to be connected to the bulb ground (or possibly the body of the switch itself) in some manner, as if maybe the bulb has its own little housing with a ground pin on it. Since the PO removed the bulb part of the harness, I don't have the bulb-connector... and thus can't verify if the bulb housing itself has the other pin (31). -So I'm stumped. Here's the wiring schematic:



Does anyone have any insight on how to correctly connect the ground wire?