Tatham was know for producing such items. There are more than a handful of SCF threads about Tatham if you use search. They did produce some respected goodies such as shown here: http://goscf.com/t/58667
I am not well versed in non-US Christmas Seals, but I will say these are not common the find now, but as Tatham produced quantities of there foldouts, they had to have some stock to produce them in their normal quantity.
Nice find as much for the paper as for the seals.