Comptometer / adding machine oil?

You're not going to want to hear this, but... Old lubricant does 'turn to glue' and cause things to stick. And adding more lubricant won't really help, you need to clean off the old first. Now I've been flamed for this before, but any _real_ clock repairer will tell you the only way to do this is to take the thing apart and clean the parts in a suitable solvent. And then put it back together with the right lubricants. As regacds what lubricant to use, I use 3 : High melthing point grease (normal car grease, Castrol LM, etc) on very slow moving parts like the carriage slideways and the handle gearing Clock oil (obtained from a watch/clockmaker's supplier) on most parts. Watch oil (a thinner version of that) on small, fast-moving parts. Not so much on calculating machines, actually, but it's what I'd use on the bearings of a camera shutter timer [1]. [1] As to what I'd use on the gear teeth in that mechanism, I wouldn't. They are designed to run dry. Maybe 1 drop of watch oil on the 'scape wheel and pallets. -tony