Years ago I got hold of a Propmasters catalogue offering for sale the personal Man from Uncle memorabilia collection of David Oliver, Propmasters founder.
Listed was a rare UK version of the Marx Man from Uncle Counterspy Set from 1966.
Unlike the US version, this one was listed with a Big Pen included.
I've never known what that Big Pen was.
This week I found out about a Marx See Through Walls pen offered as a US mail in in the Sixties. It's chunky, maybe that means big?
See what you think. Could this be the mysterious Counterspy Set big pen?