Wes,
VDO sells them new, but the diameter of the gauge face is smaller than your stock one, so you'll also need the rubber adapter ring for it to fit the larger center console hole. The gauge & sender are available anywhere selling VDO instruments, & the usual 914 new parts sources, so just get the best price.
I think that either VDO makes & sells the adapter rings, or else 914Rubber, Auto Atlanta, or others may have them.
Another option that some with the 74-76 914s with the wide red band OT gauges did back in the 70's, was the take the OT manually with the gauge pointing at a certain place on the gauge, then put a tick mark, & repeat for the range (after a few readings you could extrapolate the rise). Some added white letters for temps., & others just memorized it. Today a laser heat gun makes this easy.
Also, I think that North Hollywood Speedo &/or Palo Alto Speedo could do that for you as a custom gauge face for a stock OT gauge of the proper diameter. .... i.e.: it could be done as a numbered face.
Oddly enough, the early 73 MY brochures for the 914s, shows a numbered OT gauge in the pic of the 2L's center console! Apparently they went with the KISS red band solution in the end.
There are a few options for you to ponder!
Good Luck!
Tom
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