I'm ready to re-engage. I've documented here the effort to accumulate records from museum collections. It is a lot of work to find <200 data points from a dozen collections. Only a few of these have associated photos. Many are incomplete, without accurate localities or collector identification. And follow-up is problematic, as most records are decades old.
Recently I have become a huge fan of Inaturalist, a citizen science project that shares user observations of organisms. It is a deep dataset (<10,000,000 records). This includes some 70 observations of white witch, all of which include photos, precise locality and date info, and a user that I can email. So my next effort will be to add these to my white witch spreadsheet, and to contact contributors for more detail.