How to restore old timberland boots?

Hello everyone, just wanted to ask what’s the best way to restore my grandfather’s old timberlands? I had them cleaned and reglued already, but the boots still have some discoloration and pitting? Attached are photos of the boots. Any help would be greatly appreciated :)

I do know I may never restore these to its original color and whatnot, but I just wanted to see what I can do to make it look better and make sure it lasts longer with me! Many thanks in advance!