Ahh, thank you for the input SpeedRacer! I appreciate it, I wasn't aware of the Stubben manufacturing background. As soon as I can figure out how to get editing access to my post I will update it! I'm sure it's a close contact with a half deep seat not a GP... I've been searching Stubben's website and can't find it's official category (only a "luxury" saddle), but the way it's designed doesn't make me think GP.
This is a Stubben 31, which is a medium-wide. I can't say as to how adjustable it is- I've never custom-fit a saddle, but I do know a reputable saddlery not too far away. I could always bring mine in and ask them about it. The wool-flocked panels, I believe, should be adjustable. About the size- When I rode in this saddle I did not ride one horse consistently, so it was used on different types. I remember having one problem with a smaller pony who had very low withers and a narrow shoulder, the saddle would slide up his neck (not a problem with anyone else), and it doesn't tend to fit the narrow, tall withered TBs well (as it is a medium wide). The last I used it was on a 14.2 Arab who's a little bit on the narrow side but it worked fine for him (he had definite withers).