These are S&W 45acp mags. I think they are for the 457 457D 457S 4516 4536 4556 4596 series guns. 7 rounds, single stack, 45acp. A friend bought them thinking they were 1911 mags which they are not. Price is for all four shown. Pickup near Burtonsville MD.
Thats what I did for the MPX stocks way back - made new rails. Its cost prohibitive for the MP5 because of the 'L' rail shape. If I could get raw extruded section it would be possible. I've even thought to weld rails together but that is starting to get to be like work. All this effort for...
On a MP5 you can engrave your info down in the 'channel' that the collapsible stock rails ride in. Very unobtrusive.
LOL, Its not a printing holdup (that problem was solved w/ a new K1C), its a CNC holdup now. I'm working on the gcode to machine the slots in the rails today. so the LOP can be...
I've found follower differences too. The ASCs I have (I think it was the ASCs), I've filed the followers a little to make them reliable. Ususally just knocking the burr/edge off here and there so they don't hang.
Finding a local shop that has what you want in stock and will eFile would be fastest. Buying direct from SS and going through one of their dealers is fairly painless and only slightly slower.