Don asked about a company offering wood harmonica covers awhile back.
I also understand they've gone out of business, but for the record,
here's a couple leads [below].
As for M&M Harmonicas, weren't they the company from which Hardwood
Harmonicas was the offshoot?
My understanding is that M&M Harmonicas morphed into Hardwood Harps,
before going belly up. JRRoss, I believe, knows something about the
old M&M harps. If you look around on the web you can still find
some information about them (for instance, the HIP site and the SPAH
Industry Resource pages still have information about them), but I
don't know if it's current. I'm guessing there's still someone out
there with at least a closet full of unsold inventory...