KB5 brake spring supplier?

Altho the front and rear brake return springs for my '48 KBS-5 look good for being about 65 years old, I'd still like to find replacements.

None of my old local parts stores have them and they offer no suggestions on where to find them. Pappy Vance didn't have any either.

So where do you fellers find them?

Thanks!
Frank

Frank,
Did you look at any of the old Ford springs to see if they were the same?
Ford parts works, sometimes....