Sweden International Reply Coupons

Anyone know the story behind these fancy cancels?

Jack and Carol Yao wrote two catalogues on IRC's. Yao's Catalogue of Worldwide Reply Coupons.

You can email them. They may have an answer. Email is in this article from Linns.

https://www.linns.com/news/us-stamp...coupons.html

I doubt that the Yao's could tell you much about the postmarks on these IRCs, their catalog does not really go into those. These have the appearance of special cancels that one might find on a cover, but someone got them on an IRC instead.

The coupons shown have what Yao calls the type C design, more commonly called the Vienna design as it was approved at the UPU Congress held at Vienna in 1964.

If you are really interested in such commemorative cancellations, there is a catalog for them, available from Jay Smith
http://www.jaysmith.com/Literature/...html#a_19080