Dean, What are you doing with the 181?When I cut the dash for the gauge cluster it was pretty straight forward. I just traced the gauge bezel and drilled the hole to mount the gauges.
From the back you can see the aluminum nut rivots I used to make it easy to get the face off later.
The front edge of the dash is about 2 inches off the surface of the tub. I can't say yet whether this is good or bad but it seems to fit well in this position.
Time to start the wiring.