Ok, still playing around, dug out my other Uberti/ Navy Arms '58, also 4 digit serial in 45XX range, 1963. This one has the Uberti Gardone markings and the Ridgefield address. It also does not have a dovetailed front sight. In looking back at the older gun it looks like the rear site was squared, make sense if it was used for accurate shooting.
So it looks like Navy moved between '61 and '63 and Gregorelli Uberti changed to Uberti Gardone around the same time frame. Anyone got a '62 gun to see how it's marked?