Your revolver is the Swedish Model 1887, in 7.5mm. The serial number is on the frame and the barrel; the larger numbers stamped on the frame are unit markings, but I do not know what they mean. Those revolvers are beautifully made. Many were imported in the early 1960's; like Swedish rifles, most were in very nice condition. Original ammunition is rare, but I think ammunition is available from Fiocchi.
The gun may or may not legally be an antique (pre-1898). They were made for many years and were in service up to 1947. If we are talking about US law, I would err on the side of caution and assume that it is not an antique.
I would guess that as described it would go for around $200-250, but others may disagree. The small caliber military revolvers of that era between wars (including our own 1892 series .38 Colts) seem to hold little interest for collectors, yet are a truly fascinating chapter in the history of military handguns.
As a shooter, the Model 1887 is very accurate. For self defense, it is almost up to the .32 Magnum; I would not want to be shot with one, but there are better calibers today.
Jim