Not really sure what Masson called a "Special Die."
Here is one I would call special since it does not have any wording on it.

I am not sure the 310 Club is a special die which is why I called it a "Die Tag"
In the past I have been lucky enough to have Bud Jones and Paulson records searched for ID's.
My contacts 1st searched "invoices" then "records" then as a last resort they searched "Die Tags" Per my contacts at these companies, the ist files pitched when they get too old is invoices. Some "records" at both companies have been pitched because of age. In one case they were destroyed for other reasons. Borland!! I am told all "Die Tags" are still complete.