Hi Claire
it depends upon what clocks you intend to do I use mainly BA and small metric, although they don’t cover everything so I have a small adjustable, very early clocks seem to be all sorts of sizes.
I work on torsion clocks mainly and I am also in the uk, may I suggest if you are on Facebook join the ( How to repair pendulum clocks) group it is uk based and the admin is a conservator he does work for museums, national trust, English heritage, he knows his stuff and there are plenty of helpful people on there including myself, he has also done a lot of very good YouTube videos just search same name .
I don’t know if you intend to repair torsion clocks? If you do I have done some videos as well just search TorsionDell.
Good luck Dell
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