only as an extra hint: in Germany one of our T2 fellows build sets for the place of the clock with rev counter and more inside: in black or grey with clock or with oil temp or with oil temp and oil pressure - see: https://forum.bulli.org/viewtopic.php?p=275089#p275089 If you are thinking about an original clock in the camper, it is better to turn off the ticking with an extra switch at night. Or take the rarer, expensive original clock with auxiliary heating switch-on times, which is probably a bit quieter. I'm with VDO oil temp below the dashboard and original standard clock with extra switch - don't need more regards,
I’ve thought about a rev counter just to fill the gap but most of them have a the wrong scale so the needle hardly moves.
I have a coolant temperature gauge in the blank hole with a rev counter and oil pressure gauge up on'th dashboard
The gauge you need is the one you haven't got until you've got them all. The rev counter is the least interesting, but I don't pay much attention to any of them. If however the engine didn't seem to be running right, I might find a clue among them.
TBH one side hasn't worked for a couple of years, I extended with cheap wire which corrodes. I've got some decent multicore to fix it... somewhere.