Wow.

I might have to open up the sideplate again and do some more marvelling!

Thanks so much for your clarification. I just marvel at the fit and finish on this gun. I see several more early HEs in my future.

I have a 1946 transition M&P I have never opened- may have to go in there tomorrow!

so the SCW&W isn't explicit about this, but I gather through elimination the first "N" frame was the .44 HE triple lock?