little man,
In addition to the good advice above, if you will be applying decals yourself (it is not difficult), carefully strip the old paint from faces, rust treat the metal if necessary, prime the faces, seal the faces with a paint that somewhat matches the decal color, then apply the decal. This will keep rust from forming under the decal.
Also, you can leave the needles in place and paint them in place by "poking" the needle through a piece of paper that will lay between the needle and the gauge-face. The paper acts as a masking of the gauge face.
Tim
