Tinker's damn

[…] is not worth (to use expression excited by honest indignation) a tinker's damn : and if Mrs. Chatterly has no other salvo for her precious reputation. […]

So now, stimulated by some further experience with that world which does not care a tinker’s damn whether a verb agrees with its subject in number and person or not, she permitted the taxicab to jounce her smile out of all semblance to anything calmly superior and into a very unschoolmarmish grin.

[…] and I wouldn't sell you a tinker's damn.