You can try contacting some of these luthiers:
(from Bob Golihur's Luthier driectory -
http://www.gollihur.com/kkbass/luthiers.html):
# CO, Denver, Robert Ross, 720-201-1738, click to emailrobertross at rossdoublebass dot com • click to visit luthier web siterossdoublebass.com
Maker • Restorer of Double Basses
# CO, Paonia, Laughing Bear Instruments, Ted Moniak & Ted Birk, (970)527-4516, click to emailbasses at laughingbearinstruments dot com • click to visit luthier web sitelaughingbearinstruments.com/
Basses built to order, restorations, repairs, custom gut string sets, custom light bass tuners, handmade parts, historical repros, Smartwood(tm) fingerboards of nonendangered species, custom instruments
I do know I've read one or two posts here where folks did exactly what you're doing. I wish I could remember what the exact topic was or how I found them, but you could start by trying a search in the forum on "colorado borrow" or "colorado rent".... something like that. Just make sure you allow a lot of time ahead because if there are any other events going on, pickins' may be slim.