I'm a K frame collector, so I don't have that many N frame revolvers, and most of those I do have are new enough to have model numbers. In fact, when you add the qualifier "old" or "old school" that gets me down to only three that I've had at one time or another, and two of them were not as old as I am. Nevertheless, I'll go ahead and post pictures. The odd thing is that both of the older N frames shown here had been given front sight modifications before they came into my possession. However, except for the front sight, they were unaltered and both are wearing their original, numbered stocks.
Edit: Sorry, I just realized I forgot to mention the missing lanyard swivel on the .455. That is one more thing that is not original about it, but the hole is still there, as is the cross-pin that held the swivel in place.
.455 from the UK with no export markings:
.357 Magnum 6" from May, 1952:
The third one I once owned was a 4 screw .44 Magnum 6 1/2" revolver that dated from very early 1957. But, alas, I have no pictures of it that I can find.