Player Piano Co. sells wooden Wurlitzer valves:

  Player Piano Co.
  704 East Douglas
  Wichita, KS  67202
  tel.: 1-316-263-3241

I have a piano with these valves that someone else used.  They are
airtight but I wasn't happy with the sponge neoprene covered valves.
They are also covered with Phenoseal which is a pain to remove.

If you ever have to rebuild a Wurlitzer that has the original valves
in place then I think you should save the original valves and restore
them.  You can see one of my earlier postings on actually making the
valve parts using "Pem" fasteners and fibre [040816 MMDigest].

Don Teach - Shreveport Music Co.
Shreveport, Louisiana