What's the best non-destructive (no material removed) way to test for table flatness? I am communicating with a mouthpiece maker about a backup to a mouthpiece they made for me and I think the two that they sent both do not have flat tables, if I am checking right. I can't sand the mouthpieces...

Since I started playing again, I remember now the sore lip I'd live with. I'm playing a 2.5 Legere, and using chop-saver (I swear by that!). The mp is a pretty open Ponzol (M 110) and I'm thinking the problem might be related to the edge of the Legere, since it's plastic and got a hard edge...

I have an opportunity to pick this up but not sure about what would be a fair price for it. Any help is always appreciated 🙏

Interesting concept here. Any thoughts?