I have played GR mouthpieces for about 4 years now.
You can fill out the app and they will get in touch with you.
When I bought my first one, Gary was still accessible. Not so now.
You can also try to speak with Brian Scriver. If you email him he will return your email quickly and he will speak with on the phone if you would prefere. They are very easy to speak with, ask you a lot of questions, and LISTEN to you before they make a recommendation.
When I bought my Lawler C7, it was a bit darker in sound than my Schilke B6. I spoke with Brian about changing to a slightly smaller mouthpiece and he advised against it. He said he would make my same mouthpiece with their new T-72 backbore. It was perfect and my C7 is just as bright as my B6 was.
I highly recommend checking them out on your search for the right mouthpiece.
-cw-