Up for sale here is this NOS vintage Dumont capacitor. It is marked .01 uf 400v, and tested at .01372 uf on my meter. It is long and skinny and may not fit in a guitar, but it's pretty neat and I'm sure you could find a use. Please see my pictures for details.

US shipping and handling is $5, and international is $18. If you have any questions, please ask.

I have more capacitors and other vintage electronics listed--feel free to take a look!