I've seen a few variations, not sure how they correlate to the date of manufacturer, I think it does somewhat correlate to a later manufacturing date. Post the first three letters of your SN, and the city of manufacture(Holton/Springfield) that will give a rough indication.
Some early pistols have "Model 422" on the right side behind the ejection port. The right grip on these pistols is cut straight across from the ejection port. Later(I believe) pistols the grip came up behind the ejection port.
Beyond that most pistols had 422 on the left side, but I have seen some weird variations of others in the family that had the model on the right side.