That is a nice link to the one at Kings Lynn. Funny that I had never noticed it while visiting Lynn.
If one "Googles" tide clock one gets scores, maybe hundreds, of links to commercial makers or sellers of modern tide clocks, but original old ones seem rare. I found only a link to a very dubious one (more like a sundial) on a church in Ballintoy, Antrim, and this link
to a dreadful YouTube clip that purports to show one at Woodbridge, Suffolk. It is no longer working according to a comment!