Interesting story. The bit about patrons bringing their own stems to a tavern and affixing them to a rented bowl is new to me. I've never seen, nor heard of, a clay pipe with a detachable stem. I'd like to know the source for that.
Tavern pipes were available for a slight charge, and the proprietor would break off a bit of the stem after use, until the pipe was no longer serviceable. Between usages the pipe would get placed in the fire to clean out any dottle.
I have absolutely read about this in a book. I can't remember which, and I am out on vacation. I'll try to remember to check the book shelf when I get home.