However, I've developed another variation of this that works well in
more conventional designs.  On my gauges, the rod is secured by a pin
which passes through the gauge body and captures the rod.  This pin is
threaded on one end to accept the knurled lock screw.  On the other end
I form a button a bit larger than the rod.  Before drilling the hole for
the rod, I assemble the rod into the body with a couple of washers
holding the button proud of the body.  The lock screw holds this
assembly together as I drill the rod hole.