The re-purposed door for the potting shed (an article yet to be finished) had a really neat door bell - a manual rotary - the sort that by spinning the knob rotates a set of gears inside that in turn forces the 'clackers' out to hit the bell itself - basically works like a bicycle bell.
But after many years of ware and many coats of paint it was pretty ceased up.
I came across an idea that I needed to try - simply boil the parts in water with some dish soap.
Boil for 20 minutes, occasionally poking the paint off with a couple of forks.
Once 'cooked' remove from the water and the paint will just peal off.
Because if the intricacies of the design this bell took a few scrubs with a brush.
NOTE - if the paint is lead based, you might want to do this in a well ventilated area.