Slowly it comes to me.....
the stone is contemporary, crafted from stone, soft and easy to work. the face was ground flat and the words carefully scratched into the prepared surface
it in not a tomb stone or grave marker. it is an ashes marker. it marks where the ashes of the departed were scattered into the river
Good or it could have been a prank by the friend who “accidentally” found it.
Since it has a misspelling, it must be a hoax! /insidejoke
“it in not a tomb stone or grave marker. it is an ashes marker. it marks where the ashes of the departed were scattered into the river”
You’ve done it again, Sherlock.
—Watson.
Reading it again, it could be a carved copy of note left to a loved one by the person who was dying of an illness.
An ashes marker is a brilliant deduction!