Here is an original condition Otto Link "Reso Chamber" 6 tenor mouthpiece. It measures .087" on my gauge.
The Reso Chambers were only produced for a very short time in the late 1940's morphing into the "Tone Edge" by the 1950's. As a result, there are very few of them around today. These pieces went largely unnoticed until the 1990's when tenor saxophone legend Seamus Blake was heard using one. This was his setup for roughly 20 years.
Reso Chamber pieces feature a larger chamber than later Tone Edge designs, but tighter than their predecessors, the Eburnated Bar pieces that accompanied Tone Masters in the Link lineup. They also feature a heavy body and a nicer short baffle that really allows these to sing.
I made sure to include many photos to see the scratches on the surface. The lettering however is completely intact and it is remarkable that it survived as well as it did since it was made. One scratch looks like the number "2" on the barrel but when you see it from another angle it's just a surface scratch.