I wore them before the eighties, when they had actual collar button
loops through which was inserted a collar button of the type used for
detached collar shirts. They look neat and keep one's tie in place.
The Boar Hide Chukkas are probably an earlier version of the Viking (1)
which I wore in the '70s when I attended graduate school in Chicago.
They were perfect for the Chicago winters, unless conditions required
heavy water-repellant hiking/work boots.