Based on my TDC tool it appears it has slipped a little under 10 degrees. Of course it could be "user error", as my eyes ain't what they used to be, and I'm doing this hunched over the engine bay with a bad back, but....
But the engine is original, and I've been told by the owner more than a few times that in the interest of originality, no one has messed with anything w/o their knowledge or consent (same family since new).