Galoots

Using a try square, it's easy to transfer a knife mark from one face
of the board to the edge, as long as the intersection of the face and
edge is sharp. If the edge is deeply beveled or rounded, you need
something like a saddle square.

Knight's American Mechanical Dictionary from 1874 makes no mention of
a saddle square, nor have I seen them in some of the old catalogs. I
can't recall ever seeing one in the wild, and an old tool dealer
friend has never seen them either. Which brings me to my question:

Are saddle squares a modern invention?

If yes, what did people us to transfer marks? Folding rules?

Thank you in advance,
Chris