Try this,from Brownell's
https://www.brownells.com/guntech/Novak-Dovetail-Installation/detail.htm?lid=16679
I entered "Sight Dovetail Dimensions" in my Bing search window. A whole bunch of places to go to came up.You can research them.
This link will take you to a Bing image page with scads of dovetail drawngs
https://www.bing.com/images/search?q=sight+dovetail+dimensions&qpvt=Sight+dovetail+dimensions
so my question now is what is the preferred nominal "interference fit" for dovetail sights? My guess is .0005" to .001"?
Its really hard to put a dimension on the "feel" of a fit. If the form of both parts is(relatively) perfect,as in a reamed dowel pin hole,.0002 is tight interference.
Typically between a sight and the dovetail the "fit" is corner condition ot other hight spots that are minimal surface area and they(somewhat) swage to fit
Also there is often a slight taper to the fit.Its like saddling a horse,but backwards,as I recall. In and out from the port side.
If you have a witness line,and you just want the blinking sight to stay put,there are gap filling Loctites.
If your sight lacks a setscrew,add one! Add two!!A little drill and tap job!
Assuming your dovetail slot in your gun has not been roughly opened with a three corner file,that it is in good shape, its easy to buy more sights.
I'd leave your gun dovetail alone.
Assuming it does not rattle out,you han make a small cold chisel like tool maybe 3/16? wide? Give your sight good support and on the bottom surface of the sight gentle tap two rows of diagonal crosshatch "knurling" on the bottom of the sight dovetail. The interference of the peaks will swedge down on installation.Start shallow .You can retrace them and beat harder if necessary.