.mscx versus .mscz?

After a really dumb and unintentional delete - I just recovered a number of scores using a recovery tool called Disk Drill (Yay!). But they have all come back to me as ".mscx" files instead of ".mscz". (Actually they are zip files, but inside the zips are the .mscx files).

Is this file format OK? They seem to be usable just like .mscz.
I do notice though that when I save a score, I now have it in both formats, which is visually confusing to me.
Can I get rid of an .mscx flie once I have saved it as .mscz?

These are hundreds of files so any way I can cut down on clutter will be helpful. Thanks!!