I did all my gauges (and refinished the dash wood) when I did the rest of the interior. The gauges were a little stubborn to get apart as they put a rubber seal of some kind in between the bezel and the glass and the rest of the gauge body. Over the years this seal turns into concrete, so I had to really twist to get the bezel off, and assisted it with some very gentle prying using a very small flat blade screwdriver between the bezel and body. You can sort of twist the blade and pry up the little locking tabs on the bezel, which will release some of the pressure and allow you to more easily twist off the ring. Just go slow and be very careful, that glass can break easily. Once I got them all apart I gently cleaned some dust and whatnot off the faces, and touched up with flat black and a small model brush in a few spots where some surface rust had started to take hold. Then cleaned the glass up real well with windex. I wouldn't use any solvents on the painted gauge faces though, could take that old paint right off. This is also a good time to replace any burned out bulbs. WHen I put them back together I used a few small spots of plumbers pipe dope around the inside edge of the bezel just so that it presses tightly against the glass and body. This will keep the glass from rattling around. Now I see a guy all the time on Ebay that sells polymer O-ring sets for the Smiths gauges, if I did the job again I'd probably order those, they're cheap enough.