Just finished this set. Black walnut and maple blanks. The hardware is from Lee Valley .
The insert gets glued in the blank with the metal cap screwing on. I wasn’t super happy with the kit because it’s expensive and needs odd-sized holes. I bored undersized (7/8“) and expanded with a square end scraper, but the taper on the tubes makes it difficult to get a snug, consistent fit. Had to use some blue tape to shim the gap.
Rural Saskatchewan checking in. We don’t care what size holes you use for the pepper shaker, because we’re going to take the top off and do it right. (Maybe that’s mostly just my family, but I see others doing it, too.)