1. Mary Jane Kelly said she had a brother named Henry in the Scots Guard. Henry Sinclair, grandfather of the builder of Rosslyn Chapel, came from a family of Scots Guard. Sinclair promoted the association of Rosslyn with many Arthurian legends and Arthur Sullivan, named Arthur of course, wrote incidental music for a King Arthur opera.
You want to give me 3 similarities for a random example? Are you sure? I happen to actually believe in the Rule of Three, as expressed by Goldfinger. One is happenstance, Two is coinicidence and Three is enemy action!
I tend to think these types of Grail legend/stories/hoaxes are a vestige of the 60s. I have 2 examples starting in the 70s. A third, if you could come up with one, would at least prove to me it’s more than mere coincidence.