Quoted from stangbat:
but is there any way to update the older images to higher resolution?
Thinking about this from a database administration point of view, I would say that the old images should stay up due to the potential continued usage of links pointing directly to those images. The old image could be embedded somewhere that is depending on a specific pixel count. Plus, we should continue to recognize the contributions of the late Russ Jensen and other pioneers. Therefore, the best practice is to supplement the old ones with newer higher-resolution images.
I know that I like having the choice among multiple playfield pictures for many games.