Ok, while we wait for the topic to be moved:
I SHOULD have that frames somewhere. I kept them to have small bits of strong cardboard available, but then I never started the "project" i had in mind....
.... if you're not in a hurry, I need to dig deeply in my basement, which means it could take about a month before i'm able to tell you if they're still there or i dumped them.
Thank you very much!