Looking for a saddle for a skinny high withered thoroughbred; I don't need it super narrow, but I would like a medium narrow or maybe a medium tree that runs narrow--He's been out of work so I don't know how much his muscle will fill him out when he gets it back. Both my saddles which I LOVE are medium trees but too wide and sit right on his withers.

I need a 17.5 or possibly an 18, jumping or All Purpose. I don't have a lot of money to spend especially since I will probably have to sell my other saddles, but I thought I would ask for recommendations. I didn't know medium narrows are so hard to find! I don't like synthetics or no name saddles; I am happy to take a well-loved seriously used quality saddle that is just sitting around looking for a home. Any ideas?