Wema works
I have a 1983 37 cutter. I just installed 2 water tanks, 1 fuel and 1 head tank guage. I also installed their multi guage indicator panel.
All 37c tank guages are american 5-screw standard, and the Wema guages drop right in. They also supply replacement gaskets with the guages. Screws are standard, I had no issues with the install.
The multi-tank monitor is plastic, but it works well and has nice lighting, reads well in the dark. I installed mine under my electric panel.
So far no complaints except that the water tank overflows are not at the highest part of the tank, so the water guages can't read full. I read other owners have moved them. I may try to level the tanks first.