Recently took a pic of my S&W M&P collection
I have an S&W M&P collection also, although mine looks quite a bit different from yours.
Even though I've not gotten into polymer handguns, I was thrilled to see Smith and Wesson resurrect the "M&P"(Military and Police) name a few years back. The M&P name was used extensively for "K" frame size revolvers from 1899 until the introduction of model numbers in 1958.
Here's my collection of M&Ps, although there are a few model-marked guns in there too that I include as part of the collection due to their common lineage and essentially identical internals.
Top row, left to right: Postwar(S-serial number series) 6" M&P in 38 Special; Model of 1905 4th change 5" M&P in 32-20, and model of 1905; 4th change 4" M&P in 38 Special
Bottom Row, l to r: 6" Model 14-1, a descendent of the K-38 M&P Target Masterpiece in 38 special; 4" M&P model of 1899 in "32 Winchester"(aka 32-20), 4" Model 64-5 heavy barrel(stainless steel equivalent of the Model 10, a direct descendent of the model of 1905 38 special M&P) in 38 Special, with a factory double action only hammer.
With the exception of the 1899 model, all guns have grips that are at least correct in style and close to the same age as the gun(although the 14-1 falls on the border to where it
maybe should have diamond-center grips). The 6" M&P and the 5" 32-20 have been refinished, all others are(to my knowledge) original finish.
The major pieces I'm missing out of this set are 2" and 5" barrels in 38 Special(the 5" is a high priority for me), although I could also look for guns of all variations in both and nickel. I really would like to find some prewar target models, both in 38 special and especially in 32-20(the 32-20s have gotten pricey).