Take a real good look at the notch too, How can you tell a threaded hole was ever there,lol.
OOPs missed it by that much,lol.
That crank takes a 6-bolt FW.
The notch is just a notch, and the off-circle hole has nothing to do with the FW
My 360 crank has the same notch,
But I don't recall the extra hole.
This would be a good time to change those two core plugs
360s were never AFAIK orange