Marcos Maniacs

Greetings,
I have the Ford 4 speed with Laycock LH overdrive on my Essex V6. It is 
missing the switch that controls the reverse lights and (maybe) is the 
safety to keep the overdrive from engaging in reverse.  I can adapt a 
microswith to activate the reverse lights but am wondering if anyone 
has either a part number or at least a photograph of the proper switch 
and mounting. I've rebuilt the internal solenoid on the overdrive and 
that is now operational but would feel better if there was a secondary 
lock out in case the gearlever switch was accidentally engaged.
Thanks,
Hampton
3M5463