They are mixed together because the tags match, which makes MC consider them the same album. There are a couple of ways you could solve this issue.
Easy way: change the album tag on some of the files to reflect the reality that it is a separate release: Make it "The Final Cut (Remastered)" or something like that. This will work everywhere, and it is what I recommend you do. It will make MC consider that they are two different albums.
If you have a philosophical objection to doing that, you can take the hard way:
Modify the category in your view so instead of grouping just by [Album] you group by an expression that takes into account some other differentiating factor, like date or sample rate, or whatever distinguishes between your two copies of the same album.
You might for example put [Album]-[Year] in Expression to Group by, and just [Album] in expression to display.
This second method, in addition to requiring knowledge to implement, only has effect in the view you modify. You will also have to so modify any other views you need as well, and then you would still have to deal with the confusion in Smartlists.
Have fun...