Let me guess - the clock shaft is probaby square male and the key incert needing to be a square female. In your local shop research the various brass bolts available with hexagonal heads onto which you might find a "key" (like a specialise socket spanner) to fit. Then in the bolt studding drill a hole which is just smaller than one reqired to give a fit on your clock shaft - this could be difficult and need a micrometer and lathe (local blacksmith). Now hold the brass bolt suitably and heat it up at the at the end with the blue tip of a blowlamp flame. Offer the hot studding drilled hole onto the clock shaft and keep it their until it cools - this could be done with a hair drier on cold.
If it has worked it will be tightly held on the shaft. Has this solved the problem - I hope so.
By using expansion and contraction you may well come up with a better technique.
Nyge, March 2011
