Maroon Gem Half Nut Question

[Couch Potato]

I have a Maroon Gem with the half nut assembly as shown below left. It is clearly missing the adjusting set screw. Is that set screw (or perhaps round head screw) a #5-40 machine screw? Also, do all Maroon Gems have that adjustment? I ask because when I compare it to my Model A Gem that machine has no adjustment screw nor the piece to hold it and it works just fine. Thoughts?

[JerryVan]

Also, do all Maroon Gems have that adjustment?

My Model D, Maroon Gem has the same adjustment. My Model C, Gem does not. Apparently, it was introduced with the Model D.

[Andersun]

All the Gem Ds and Es had them. I got one I can send to you. Just PM me your address.