Just wanted to chime in here.
Recently have gone through fitting issues with my gelding.
Best investment EVER has been a Flexicurve to do saddle tracings- takes me WAY less time than messing with a wire hanger (which I tried first, but didn't think I was getting it as accurate as I would lhave liked and the horse didn't think my prodding was very polite on his sore back)
I bought mine for about $12 at my local JoAnns.
Saddlebred backs can be deceptive, I think. I used to have a wide tree saddle and it was too wide for my first mare who was built like a tank with a HUGE barrel.
but with my current gelding, who is pretty narrow and can use a 40" show girth, his tracings actually put him comfortably out of your average wide tree. I had a Stubben Tristan (32 cm tree- 31 to 32 are Stubben's Wide trees)
I have an all purpose saddle en route to me thanks to Hastilow Saddlery- a Cob model Thorowgood T6 which they think could work for Andy based on my tracings. (Trumbull Mountain will do the same thing, i believe) I did my tracings using their instructions: http://www.hastilowusa.com/old-site/...-fitting.shtml
More in depth than a simple wither tracing- also gives you an idea of how curvy the horse's back is, the angles that the saddle panels would need to take at the rear of the saddle, etc.... If you're having trouble getting a horse's back comfortable, it may be worthwhile to seek out a fitter... Hastilow didn't charge for the service for their certified fitter to analyze the tracing. Looking forward to receiving the saddle and seeing how it works.