4 valve York Eb sousaphone

[Lew]

If I didn't already have a Conn 28K, I would have been tempted by this:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... %3AIT&rd=1

$650 for a 4 valve York sousaphone sounds like a bargain, even if it needs a valve job. What would it take to add a 5th valve to one of these? Has anyone done it? I would think that the rotary 5th valve from a Meinl-Weston 2141 would work. I just wonder if the tubing could be made to fit in the sousaphone wrap?

I think a 5 valve Eb sousaphone would be a great horn to have. I love the way the 4 valve plays, but there are some notes a 5th valve would really help intonation, like low Ab, G, or F, which are pretty common.