Had to leave this for a while .
Coming back slowly with the sorting of the
oil pressure gauge and switch.
I was gonna have the switch off the rear of the engine but the lines look good and I dont want to mess with them.
At the front of the engine there is a handy port to the
oil system.
So I re-purposed a brass fitting , it has 3 off 1/8 NPT threaded holes , 1 for the feed , 1 for the gauge and one for the switch:

I dont have the switch yet.
Thanks for lookin' and not commenting.