SHASTOCK CUP MUTE
VINTAGE MUTE - LIGHT RESTORATION
Here's an example from around the 1950's to 1960's.
It has had a very light restoration from professional trumpet player/recording artist - Jimmy Smith who runs Smith Mute Restorations in Detroit, Michigan. Corks are replaced, dents removed and a light spray of lacquer I believe.
Shastock Cup mutes are widely used in Band, Studio and Commercial applications.
The adjustable aluminium cup makes this an extremely versatile mute which is why they remain popular today