Checking that it is in the proper SN range and that the topstrap stamping looks correct is about all you can do without getting a letter. You should also ensure the grip SN stamping matches. There are some Navy-stamped pre-Victories.

"As noted by Jeff above, the sideplate-marked guns are different due to their relative rarity."
True, but adding that frame engraving would be very simple for a faker to perform, as it was not done by S&W.