No, don't stop using the older images! They were the most fun for me! Reasoning about the political landscape that would have led to the beach photo was challenging and rewarding when I got it right. And the London Blitz photo was also a ton of fun to see and think about.
Adding to the chorus: I like the older images and the precise year is important! The underground shelter is something that wouldn’t exist just a few years after that photo, or before.
For the record, I especially enjoyed the older photos. Maybe it's just a matter of making it obvious in the UI that they penalize less, so that score maximizers won't be annoyed with them.
This is fun. One tiny bit of UI feedback - when maximising the image, I'd expect the escape key to go back to the game, and found it a bit frustrating when it didn't.
Also, older photos are scored more generously, so being a few decades off won’t tank your score nearly as much as it would on a newer one.