I've two brilliant and highly skilled retired engineer pals. Both lifelong Brit bike enthusiasts - one a pattern maker (at one time for Vincent cylinder head castings), the other a plastic injection mould and tool maker who did, among other things, specialist BSA crankshaft work. Both when retired brought home their lathes, milling machines etc. and continued to produce small batch stuff more or less for pocket money and to keep themselves and their brains active.
Both now only do the occasional one-off 'interesting' stuff for biking friends whenever they feel well enough from age-related infirmity; arthritis etc. but we still swap 'blokey' bike anecdotes over a brew in their sheds though (when permitted).