Hey all!
O.K. I'm new here, so bear with me... Not to steal anyone's thunder, but I have some info for anyone who wantes to make an accurate GB themselves.
www.nationalbridle.com sells 14 strand english mohair girth belts for $11.95. The caveat, of course, is that they are white, and you must dye them the appropriate marroon yourself.
You can find them cheaper, for around $7.50, but beware, those ones are rayon/poly and will not dye properly.
Again, not to take away from any of the talented folk who make and sell them here (And an exquisite job at that), I'm just the sort that likes to build it myself. That's half the fun.
Enjoy!
ShinobiFett