I believe the comment about not being a found item was in reference to us speculating on how the screen used ones were made. I just found this video from the Matter Hackers Halloween Party.
Now, Frank starts out saying all the props are designed by his shop and 3d printed, then sort of walks it back a little, and makes no reference to the sidearm. This did just wander into my youtube feed, though, and now that I have a name, I can start looking to see if Mr. Ippolito has anything more to say about the originals.
I think it’s interesting that they don’t paint the props, that the colors are all part of the casting process to avoid issues with chipping the paint on set.