San Remo was an engraving pattern/grade; i.e., it was a "grade II" for the lack of a better term - that is, until the Munchen grade came out in late 32 production. Then, I suppose you would say the San Remo was a grade 3. Trouble is, the San Remo still had Roman Numeral "II" on it, whereas the Munchen had "IX" on it.
I believe a San Remo could have been anything you wanted from anything which was offered at the time of manufacture. I have had two Model 32 Kriggys that were field gun choked, as verified by KI in Ottsville. Hal du Pont was a great businessman and understood fulfilling the customer's desire was the way to success.
Having stated that, many, many M32 guns have been modified, swapped, etc., today. In fact, it is still going on at a very rapid pace. At some point in the future an original factory verified 2-barrel trap combo, or an original factory verified 4-barrel skeet set is going to become rare and perhaps more desirable, regardless of grade of engraving. Not to mention a more rare live pigeon Crown Grade gun or something along those lines......