The shifter boss are Campagnolo. My understanding is that this particular style was introduced in 1955, so the frame should be no older than that.

The first image in post #4 shows what appears to be faux lugs. The lugs appear to be stamped impressions in the headtube, as you can see the outline of the lugs on the inside of the head tube. I'd appreciate if the OP would verify this. This was a common method to economize. A flat sheet was stamped then rolled and welded to form the head tube and lugs.

The brakes, are entry level Universal Sports. I'm not sure exactly when they were introduced, but some time after the Universal 61, in 1961.

I'd still like to see a picture of the crankset, shifters and derailleurs, if you have them. Currently, there are some conflicting features. It has shifter bosses, yet features what appears to a stamped headtube with faux lugs.