Last time I needed washers for my hot bulb lamps, I cut
them from leather myself. Easy enough.
If you are in a rural area, the local farmer's supplies tends
to be brilliant for all sorts of stuff not regularly seen in
today's urban hardware shops.
I needed to construct a custom back-fill bleeding kit for
a recalcitrant master cylinder this week, & needed a big
syringe, meths (to avoid damaging rubber seals), clear
Drew a blank at all the usual pharmacies & auto factors,
but got the lot for very little money at the farm suppliers.
Told them that the combination of fixed pension & crazy
council tax had driven me to mainlining meths ....
Also, if you still have a local traditional cobbler, they can
probably help for very little money. That's where I sourced
my leather offcuts for my DIY exercise.
That apart, I'm sure Google would turn up sources, 'tho
I now try to keep the traditional suppliers going, before
they all retire ....