Maybe Perkin did have a fiddle but it was destroyed when the mill was "broken down." That sounds like it collapsed. Pepys didn't say that the mill broke down, like an old car, but that the wind broke the mill down).

Surely Perkin must've had a fiddle and kept in practice on it, or he wouldn't have thought he could make a living playing one. Maybe he kept it at the mill so he could play while the grain was being ground, using the machine noises as back-up percussion.

That still wouldn't prove that he played it for pleasure, though. It may have been a side job, to supplement the meager income he got from the rickety old mill that was so susceptible to damage. It sounds like the old clunker wasn't worth rebuilding, and maybe it didn't provide enough income to pay for insurance or to build up a nest egg to repair it or build a new one, or even to buy a fiddle.