Latest map version

To add to this - If I try to remove it, it asks if I want to remove the 2023.10 map! so one part thinks I already have the latest - how can I verify which version I have?

It's automatic, don't worry about it.  There must be something else more deserving of your time.

Do you really need two continents worth of maps on your device?

If you must worry about.  What makes you so sure the versions for different regions must match? 

Be certain, as the user you are not making the problem worse.  If it says it has to uninstall a map to meet your request, why do you think it's not doing what you asked it to do.  Maybe it must uninstall all maps and then reinstall.

Tip: If you run JaVaWa's Device Manager from https://www.javawa.nl/jdm_en.html you get an overview of installed maps, filenames, versions, size, date and a lot of options to manage the maps on your device.

but it doesn't tell you which map version you have...

On the main screen: press Manage Maps, then expand the resulting window. The map versions are in the column 'Map set name'.

Thanks for that - I also saw how to see what is actually on the unit. 

The maps also include some SQL database files of Climbs that take up space as well.

Look in the Garmin\SQL\Internal folder