You may have to do the merge again so you can make the images anchored objects. then both they and your paragraph styles can be set relative to the spine. I'm not so sure you really wnat right alighed text, though, in a catalog. It can be hard to read. Snapping your text frames to to column guides with sufficient gutter, to hold the images would allow the images to swap sides but the text to remain left aligned, if that would work better.
You're correct, it's not the text I want aligned as much as it is the images to swap sides. I'm relatively new at this - any instructions as to how to make this happen? Do you know of a video I can watch/section of help to read so I can do it quickly?
Thanks again for all your help.
Tyhe two things you need to read about are Anchored Objects and Layout Adjustment.
With Layout Adjustment enabled, text frames that are sanpped to guides will move and or resize with changes to the guide positions thay are snapped to, so you can set up the margis or columns to hold just the text and anchor your images in the margin/gutter. Then you can switch to a new master with a mirrored asymetrical layout and the frames should move. Withte Anchored objects set as custom positoned, and relative to spine, they should also swap sides on opposite pages. Sounds harder, and more confusing, than it is in reality, but the image frames are going to need to be anchored, and it's easier to do that before the merge than after.