I'm building up a Wikipedia <-> LCSH crosswalk for the Forward to Libraries
service that I maintain. Some of the crosswalk is automatically generated
based on identical or similar headings; some of it is manually maintained
in a "wikimap" file. That manual file currently has just over 6,000
entries, and is available as CC0 data from Github:
https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap
Between the manual file, the automatic matchups, and the name correspondences
provided by VIAF, my forwarding service can map between over 300,000
names and topical subjects in Wikipedia, LCSH, and LC name authorities.
Folks are welcome to reuse my crosswalk file or contribute further updated
to it. Or, if there's somewhere useful to embed this sort of information
in Wikidata, I'm open to using that for getting or maintaining crosswalk data.
John