The website of the on-site archaeological research institute and museum, run by Fukui Prefecture, is an incredible resource for all students of Japanese history. The museum updated its website in 2022, which included removing the English-language sections of the website, though this may be temporary as they build the English pages.
Four resources are clustered together in what the museum calls the “Historical Materials Database,” which actually consists of three searchable “archives” and a bibliography of museum publications:
The “Archaeological Data Digital Archive” allows users to search by activities of daily life (getting dressed, eating, praying, etc.), materials (ceramics, metal, wood, etc.), place of excavation, and so on.
The “Stonework Digital Archive” allows users to search through more than 2200 excavated stone relics from Ichijōdani, the majority of which are stone buddhas and stone stupas of the sort analyzed in chapter 4 of the book.
The “Book List” presents all of the publications of the museum in Japanese; unfortunately, these are merely citations, not links to PDF versions of the excavation reports, catalogues, and research publications, which would be much more useful for researchers.
On your next trip to Japan, plan on visiting Ichijōdani, which is just a short train, bus, or tax ride from Fukui station. The valley is beautiful, the archaeological sites and outdoor locations are amazing, the “reconstructed town” is exciting if somewhat puzzling, and the main museum (which is located just outside of the valley, across the Asuwa river, near the train station) is certainly worth an hour of your time.