Can you find me a retail source for a wooden reed (key of C ) for a
bombard (early medieval wind instrument)?  Someone suggested a shop in
Boston,  but I cannot find any reference to it.

Hello,

Here is a link which I think supplies exactly what you're looking for
in your search for a reed for your Bombard(e).

Bombarde FAQ
http://texcelt.org/Bombarde/#Reeds

The above link gives the name and address of a gentleman that can
manufactor the reeds that you are searching for. According to the FAQ
he will make them for sale in bulk or in smaller quantities.

Google Search Terms
"Bombarde" +reed +buy

Regards,
Dandrick-ga

The following link will get you to the Ancestral Instruments Website,
where they offer a bombard (in C) double reed for $195.

http://www.ancestral.co.uk/prices.htm