That looks like a new 37. The newest one I’ve had was made in 1963, and those grooves aren’t present.
BTW, any shotgun with a vent rib can make use of a Meadow Creek mount for a red dot. The one I have puts a FF3 really low on the rib. I’ve used it on a CZ O/U and by happy coincidence the same base fits my Gold Hunter 20ga. Very solid.
