You could get the Orings at HomeDepot (Fastner Harware isle) or
This comes up under torches now and then, too. O rings is O
rings… Torch and valve makers don’t make special O rings, they
go to the hardware store (so to speak). Aerospace makes their own,
if needed, others rarely - it does happen, I suppose.
But when you need a new one for your torch handle or wax pot, it’s
not going to be a special part - they are commodoties just like
screws and nuts. As long as it’s the right size - ID and OD, which
is determined by the width of the stock, it will work just fine.
They come in a bewildering array - big and skinny and small and fat,
so you need to be careful about the size, especially if it’s gas,
but O rings is O rings…