5th Valve Addition TU330CC

[TubaDude]

Has anyone had a 5th valve added to a Holton TU330CC? If so, who did the modification and where are they located?

Here's a few pictures of the horn:
Front View

Tuning Slide Knuckle out of 4th Valve

Tuning Slide up to Bugle

Lead pipe into 1st Valve

Main Crook 45 bend out to Bugle

Back of Horn View


All slides are currently frozen, so all measurements were taken with a micrometer on the outside surfaces:
Lead pipe .660"
Knuckle out of 4th valve .743"
Outer tuning slide from 4th valve .773"
Inner tuning slide from 4th valve .732"
Inner tuning slide to bugle .798"
Outer tuning slide to bugle .844"
Main tube to bugle .804"

Thank you all,
Tubadude