Best Laid Plans

Didn't get as much time to work on my threaded stand off today, but I tapped the 12-32 NEF internal thread and then relieved it 1/10 inch at the top, as the original is.  That sort of stuff takes a few minutes.  I didn't cut the slot, which is a 1/16" wide slot that appears to be for driving it with a large screwdriver.  This top picture has the screw that it will work in most of the way in place. 

The slot is probably one pass on the mill (I need to look at that and see how deep the cut is to be sure).  It will definitely take more time to set up the cut than to make it.  I just ran out of time to get it done today.