I have taken my TVR dashboard appart to re-cover it.....the old smiths glass faced dials are a bit manky...both inside and outside...

What is the best way to clean them? Can I get them appart to clean the lenses/faces without screwing them up?

Do they need oiling?

I just very carefully took mine apart, used warm water and dried them off immediately. Lift tabs with a small screwdriver and remove retaining ring. Mark position of needles on side of case. Prize needle off very carefully (a fork is good!) and remove face (some have small screws). Whwn you put them back together line the needle back up with the mark you made.

http://www.caigauge.com/ Should be able to recondition them for you as they made them in the first place. Speak to Ian John in the technical department.

look at the back - some smiths guages, as fitted to series land rover, have cut outs in the bezel so all you need to do is twist the bezel until the tabs line up with the cut out and then the bezel and glass come off.

others wyou need to use a screw driver or sturdy kniffe to unbend the bezel.

once inside, you can clean as mentioned, maybe meths would remove oily stains.

the mechanical parts can be oiled or greased but don't over do it.

don't attempt to pull the needle off.