I could not find a date anywhere on these puzzles, but if I had to guess, I would put them in the late 60s to 70s range.  Two of the puzzles have a piece missing out of it and the other two are complete (as you see from pics).  They do show some wear from usage over the years, but they are suitable for play or collecting.  Classic pieces of late 20th century Americana.  Thanks and good luck.