It looks like many of the commonly upgraded Victory models done after WW2 in Germany for US Service personnel.
The bbl rib and front sight ramp is a commonly seen add-on. The engrving pattern is common to them as is the jeweled trigger and hammer. Many of those revolvers sported ivory grips, but stag and other mat'rl were also common.
I'd suspect the cylinder to be a replacement from since the gun was engraved since it is not engraved. But you never know what a customer may have wanted.

Silver line and figure inlay was a very common feature, gold work not as much but you do see them.
The guns were common and cheap after the War, as was the local German gunsmithing and engraving labor force, or what ws left of it.
Those tradespersons worked for nearly nothing,,sometimes just food, for their trade talent to stay alive at first.
The German civilian population was not allowed to own firearms especially handguns early on, so an industry popped up on the US bases to do this type of work.
One of the largest was Kurt Jaeger. He employed many engravers and gunsmiths, though the work was generally signed with his name on it.

Most of these guns ended up coming 'home' to the USA with the returning GI. They show up for sale here and there as the guns get put up for sale over time. Most any large gunshow will have at least one around if you look long enough.

As to the missing ser#.
It obviously had a ser# on the bottom of the butt when mfg'd. S&W always ser#'d their revolvers.
-Ser#'s were in fact required on firearms before the GCA68. At least since the FederalFirearms Act1938.
The two classes of firearms exempt from ser#'g by their mgf'r were cal22rf long guns, and any smooth bore shotgun (long gun).

These two classes were exempt from ser#'s though many mfg'rs chose to ser# some or all of their production of these anyway.

Centerfire caliber rifles & any handgun were required to be ser#d by their mfg'r right along.
The only thing the GCA68 did was add those last 2 previously exempt catagorys (cal22rf long guns and any shotguns) to the 'must be ser#d' catagory.
This makes the GCA68 responsible for 'all firearms being mf'd after '68 must be ser#'d.

A removed, altered, obliterated mfg'rs ser# is just that and addressed directly in the GCA68 and in all 50 states firearms regulations separately.
It's just plainly a violation to under take that operation or to possess or transfer a firearm with a ser# as such.

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