Masks - Can't seem to get it right

[AceMcHammer]

I'm running GIMP 2.10.20 on Windows 10 on a 4K screen.

I searched for and found various GIMP mask tutorials but for some reason it never comes out right.  

I have a specific image that I'm trying to "enhance" with a mask.  BTW, this image is a copyright released image found here for any would-be copyright nazis out there.

I'm trying to get this image here.......




to look like this image here.........




As you can see the second image has a very light sort of sepia tint to it and I'm guessing they made a mask over the whole image.  So if I like the second image better then why don't I just use the second image?  I have a higher resolution image of this image than the one that I found online that's been masked and in addition to that the second image has been cropped and I want to use the uncropped image.  

Can someone give me detailed instruction on how to get the first image to look exactly like the second image by making a mask?  Thanks in advance