The earliest gold boxes for the M&P that I have identified shipped in August, 1946, on revolvers in the S83xxxx range. The earliest one came with a 5" gun (a simple fact, that really tells us nothing).
They were being phased out in favor of the blue boxes in the mid-1950s. The latest one I personally own is from 1956. I have a couple 1957 guns and some from even earlier that came in blue boxes.
However, we know some gold boxes were still in inventory as late as about 1960 or 1961. It is noteworthy that the only gold boxes I've seen from the 1960s were associated with target K frames, specifically the K-32. Since that one was a slow seller, it makes sense.