We did some browsing in a thrift store yesterday, and just happened to find the big cork board now hung beside the stairs. $15.00! It's just about the right size for my original piece from the workshop. I had put it aside because there was nowhere to stretch it out and sandwich it. Now I think I will be able to do it on the concrete floor behind the cabinet.
AND last but not least I've made some good progress on "Filmstrip" as I'm calling it for now. I connected the filmstrips to each of the orange blocks, then I started developing the second block according to the various versions I'd created. I finally took a break because I can't quite decide if I want to make them asymmetrical, or two-part like the first four, or just make the purple strips wider.
THEN, I have to come up with the third block, of which there will be only two. I don't have any solid idea at all but I am very much looking forward to allowing myself to improvise.