Aren't those beautiful! I have bought a print similar to the one on the right and it was called a 40s reproduction. I think they're probably both from the 40's, but I'm no expert, just a collector/stash builder. As you say, a scrap bag can contain many decades' worth of prints. I've bought quilt tops that had everything from the 30s to the 70s in them.
I wish that one on the left was available as yardage right now! Both of them, but I've never seen anything like that one on the left - I'd like to make a dress out of that.
Good luck with your project - I hope it comes out just great.