Mexican Imperial?

[Parmcat]

I think these have been referred to as that name.

Thanks

[Chad G.]

This may help, I'm a little lacking on the subject, never collected either. Make sure ya read the whole post, I had to to grasp what they where talking about. Good luck Brother, hopefully ya run into a collector of such.

 

LINK ::     https://www.allaboutmarbles.com/viewtopic.php?t=52483