Key Bottle Mark on Base ?

[Reelpro]

Anyone know a glass maker that used an old fashioned key as bottle mark on base in center of photo.

Hand blown glass - purpled

 

[Reelpro]

 

[Reelpro]

No joy, looked through bottle marks on bases till eyes were buggy.

cannot find a key like the one on this old purple bottle/jar ?

any ideas for bottle mark sources , experts ?