This is one of the puzzle types I've been trying to do. Each is 9x12. Two of them are 165 pieces, the other two are 140 piece puzzles (they're not easy).
The top images are from a 50 cent booklet I got at the Friends of the Library bookstore, glued on with contact cement. The artist is Paul Detlefsen and the book is one in a series of 8 that I'm looking for.
The wood is 1/4" 5-ply. I wasn't too happy with it. The boards were 12x24 and I had one board curl and twist like a strand of DNA, two that had a lot of internal voids, and one that actually had a football-shaped plug on both faces - something I didn't think was possible so I didn't look for it and didn't find until I was ready for glue-up. I was able to work around most of it but there should be a 5th puzzle in the set that got ruined when I stumbled on a big void.
I'm building the small boxes to hold them now, and then I'll be working on a series of 10 small (4.5" x 6" ) watercolor paintings that I'll cut into approx. 20 pieces each - just something easy that someone can assemble while taking a tea break.