http://historical.ha.com/c/item.zx?s...05&lotNo=32250
BU proof stampings look very light on the left side. might be a redo.
pin thru toggle knob looks blued. might be a redo.
the 173,xx is the old way of indicating the barrel is in 7.65 caliber.
since the gun is a civilian gun and not military, the holster in the photo may be one for a civilian buyer. military holsters have swiss proof markings, under the closing flap.