[wwwwewwww]

Would this further extend to fishing or hunting licenses?

I think I one could say that fishing or hunting licenses only apply to certain locations - you are only able to use methods X in location Y. This out of state the license is valid but not useful.

Then the question is whether gun license is more like a marriage licet or a hunting license.

[zacharyvoase]

Well a marriage license is not actually a document certifying that you are married, it is a document granting you the right to get married in the state that issued it. You can't get a marriage license in Indiana and use it to get married in Illinois.

Once you do get married, though, the marriage itself becomes a public record of the state that would be protected under the Full Faith & Credit clause. But as I mentioned in my previous comment, Obergefell v. Hodges had absolutely nothing to do with marriage licensing and states recognizing each other's licenses.

[ashtonkem]

I believe that the state could argue a compelling interest in hunting/fishing licenses, since they affect resources spent by the state. It’s already legal for such licenses to be more expensive for out of state visitors, for a similar reason.

IANAL.