Please refer "Smiths Gauges", I posted in June 2021.
I have photo's on record if of any help.
Hardest part can be removing the chrome bezel - I ended up buying a cheap plastic/rubber strap wrench to assist with this.
Be VERY careful cleaning the actual face - the figures are VERY easily removed - I simply used a small sable paint brush.
Having done too many to count of these...basically to transfer over the half round bezels onto new gauges...couple things to have at hand:
1. a tiny flat head screwdriver. Those tabs on the back of the bezel that hold the bezel on MAY BE a bit tight after half a century and who knows how much corrosion on the gauge case flange to make it easy to turn. Relieving it A LITTLE by prying up under both ends of the 3 tabs will make it easier to rotate the bezel.
2. gaskets and o-rings. At this point, they will be hardened and crumbly. Get a stock of the proper size rings so when you put it all back together, you won't suffer from the rattling glass syndrome.
3. As Dilkris mentions, a gentle sable paint brush to clean off the dust. No solvents, no windex, no nothing. What you got is what you got re the face.
4. If you're brave, and you want to pull the gauge bits out carefully, giving the inside of the case a light paint job of gloss white will help with illumination (nothing really helps a lot...on my turboesprit, I ended up buying post lights from aircraft spruce and mounting them on the substrate like in my cessna, then drilling out the plastic overlay so they poked through and wiring all up to the dimmer. At least then I could see the gauges!)
Clean the glass really well (wear nitrile gloves to put all back together, nothing more aggro that lighting up the gauge and seeing a fat fingerprint on the INSIDE of the glass!), install new gaskets/o-rings. put bezel/glass/gaskets/etc face down on soft surface (microfiber cloth folded up works well), introduce gauge case to bezel, push solidly down and twist (or, if you've straightened up those small tabs...you only get one straightening until you weaken them...ask me how I know, position the case so the tabs are centered between the cutouts in the case flange) and re-tighten the tabs etc.
HTH. Or, you can send them to me and I'll be happy to help...l9l.