[Alex van de Wetering]

Paul,

I have no experience with this, but would try a corner with some WD-40, Or maybe start with just a brush and soapy water and finish with a coat of wax.

If your going the route of re-doing the faces....most Chev parts suppliers offer stickers or waters slide decals to make the faces look like new. They also provide new needles; I have bought new face stickers and needle from the Filling Station in the US.
LWDparts also offers NOS gauges if needed, as does Jeepest and JeepVillage in France.

Alex