Yes, Kris, I can give you some information.
1.- It's not a stamp, but a cinderella, issued on December, 27th, 1985 by Barcelona's Stamps and Coins mercants Gild.
2.- It was issued as a mini-sheet with 7 other cinderellas (4 with just Catalan text, 3 with images),devoted to late XIX and early XX century Catalan artists like Sert (he has some frescos on NYC's Rockefeller Center), Miró and Dalí. I guess, you've some references about them.
4.- It was part of a cinderellas' series showing Catalonia'a history. The series ran from 1977 up to early 90's.
5.- They were sold at "face value" at the Gild's stand on most Catalonia fairs.
This one was issued on the December 1985/January 1986 Barcelona's Xmas Children Fair
6.- Despite their name "segells de Catalunya" (Catalonia's stamps)they were never sold as "stamps". It was clear, and all of us knew it,that they were just cinderellas. Although, many people bought them for Catalan patriotisme. But, never were pretended to be used as postage stamps. Personally I rejected them, until I become interested on cinderellas, and now I've most of the mini-sheets.
Another thing, is what some internet salespeople write on their description.
7.- They can be found on my late friend Sebastiŕ Sabaté catalog of Catalan tňpic stamps and cinderellas.
8.- We always collect them as whole mini-sheets, never as single "stamp".In Barcelona, you can find them for 1 or 2 €.
9.- They can also be found unperforated or with the red overprint "Mostra" ("sample"). These, comand a Premium, as they're less common.
10.- The Money was for the Gild's Philatelic Activity. This was also clear. They were never sold as charity stamps. We Catalans, like to be very clear on these qüestions.
11.- "Face value" was in pesseta, our currency up to January 2002. The 50 pta of the "stamp" was equivalent at today's 0.30 €. By then, they weren't cheap at all.

