Unbranded Trumpet Mouthpiece number 11

Description

Cleaning out my personal mouthpiece collection...
Got an interesting trumpet mouthpiece.
Unbranded except for the number 11...almost looks like an Al Cass but I'm thinking it's more likely an OEM King made piece for dealers to toss in with rentals (like Herco and Coast mouthpieces).
Feels like a 6C to my face...throat is a #26 (but it hasn't been opened the plating is still in the throat).
Playable shape overall, looks like it's 50 plus years old and "art deco-ish".
Might be collectable/might be the holy grail you've been searching for your entire career.
You decide.
Examine the pics closely please
Will sell for ( plus USPS Priority Mail)
NO INTERNATIONAL SHIPPING
NO RETURNS
**we do not offer returns unless item was described incorrectly**
Message me with any questions.
Thanks for looking!