I believe that the bookshop in Grosmont has now closed, with https://www.mrslofthouse.co.uk/2022/02/16/about-our-store/ in Scarborough buying up a lot of his stock. (no connection other then as an occasional buyer and seller of books to them!) Got a fair selection in there. As for buying, they do cherry pick stuff they can sell, and are keen for books on diesels or local railway. Hope that helps.