Hello Revbusnut, and welcome to the board!
Well, I'm certainly on the newbee side of the house when it comes to actually working on my bus. But I do know that Rich @ International Bus Parts does carry lots of air system parts replacements. And he is very helpful as well. So, you might consider giving him a call to get some thoughts, and maybe some parts, for your project.
Rich is a regular advertiser on MAKs web site and magazine.
He is @ http://www.1800intlbus.com/
- or 800.468.5287
Hope this helps, Phil