Eric,
Being a late model CMP,
Common Spares were employed, (EG Chev, Ford, Dodge, Jeep, GMC, Diamond etc) and these these instruments are Stewart Warner
http://stewartwarner.com/ Note Impedence and/or resisitance must be known for each circuit, and its respective detector, as they vary from each truck circuit variety, BUT can be corrected. (Bob..... I am Keeping it simple) It mentions this on the S.W. website, with respect to fuel systems.
You are fortunate as you can get replacement parts from them OR New Old Stock which share commonality with many trucks. If they have a NSN you might trace that to New Old Stock or a Surplus set.
If the mechanism is ok behind the dial you have the task of repainting (or getting a repaint) done. The dial may be available from S.W.
If the mechanism is totally destroyed then S.W. may have that too, otherwise New Old Stock parts, again, may help.
(That is the Very Short version of a rather long winded answer).
Ian