The mag catch assembly used on the Value/CS series doesn't use a threaded nut like the standard style mag catch assemblies. The plastic mag catch nut snaps on & off, being retained on the shaft of the mag catch body by an inner ring on the nut which snaps over the head of the body's shaft. They plastic nut is a "Use Once & Replace" part, though. We were told it's not recommended to remove the plastic mag catch nut except for repair purpose.
The nice thing about them is that there's no adjustment required during installation like there is with the standard mag catch assembly, and because of this installation is simpler. (Not only does the mag catch not need to be adjusted, but there's no plunger which can fly away and become lost.
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Here's a couple pictures of the brief instructions given to armorers regarding this assembly, as well as a somewhat grainy picture of the assembly.
Here's an image of the Value Line mag catch nut & mag catch body and the standard mag catch nut and mag catch body. You can see how the Value Line mag catch body has a 'head' over which a raised ring inside the plastic nut's hole is slipped and snapped over it. You can't see the inner ring inside the nut due to the light and my old camera. FWIW, on the back side of the standard metal mag catch nut you can see the recessed slot into which the plunger head fits when adjusting the mag catch body (turning it 180 degrees at a time) for depth and reach.
Interestingly enough, I've not yet had to replace a plastic nut or metal mag catch body on a Value Line or Chief's Special model, but I've had to replace a few standard mag catch assemblies on both new and old pistols.
I've also had some number of the small plunger springs become badly rusted, and the spring holes become filled with grit & debris, causing difficulty in mag catch operation in some guns with the standard assembly. Apparently the narrow & deep spring hole for the standard plunger spring doesn't allow for moisture/liquid to easily run out, letting it become trapped, and probably doesn't allow for much air circulation, either. While the original mag catch assembly allowed for adjustment to optimally position the mag catch body in the frame so it could catch & hold magazines, it came with it's own disadvantages, too.
Of course, in the newer TSW guns the standard mag catches could be reversed or changed for left-handed users, depending on the frame. The same part could be removed and installed from the other side in the newest 9/.40 double column mag TSW frames (because of machining changes in how the frames were made), but not in the single column .45 frames. S&W finally made a left-handed mag catch assembly which could be ordered and installed for left-handed shooters of newer .45's.
In my first armorer class it was recommended that we use a file to notch a regular screw driver blade tip and create a sort of 'spanner wrench' which would make it easier to install and adjust the threaded mag catch nuts. That became handy over the years.