Conn George Roberts mouthpiece

[bigbandbone]

Does anyone have any experience playing Conn George Roberts bass bone mouthpiece? There’s one for sale on FB Marketplace hat has me curious.

I’m currently playing a Macinkowitz (spelling?) 1 1/2 which used to be there George Roberts model until he switched to something else.

Did GR experiment with a lot of mouthpieces? What did he finally settle on?

[modelerdc]

I had one, it was close to a 1 1/2G in size, felt a little larger, the rim was rounder toward the inside, the throat a little larger. If your looking for something the the 1 1/2G size it's worth a try.

[Bach5G]

I think slightly oversize 1 and 1/2 kind of captures it.

[MStarke]

I play mouthpieces approximately in that size on bass and also own a Conn Roberts. I have tried it briefly a few times on different trombones and honestly always put it away again after a few minutes. Somehow it doesn't respond well and feels not optimal. I cannot say what's the reason, but it seems somehow unbalanced. Not like other "GR-inspired" pieces that I have played.