25-65 USD
Small handgun
small .22 or .25 caliber handgun
S&W never made a 25 ACP handgun for retail sale.
No published sn data.
50-200 or so
10-1000 USD depending on specifics
As long as it's the correct caliber, yes.
The short answer is no. The longer answer is, you may be able to get a .25 cartridge into a .22 caliber gun, but it will likely jam and be very difficult to get out, and if it fires, it will probably damage the gun and possible the shooter. The .25 has a larger diameter than the .22.
$25 or so. Low value handgun.
Generally it is a small concealable auto loading pistol of limited power. It takes its name from the .25 ACP cartridge that it fires. It is called .25 caliber (notice the decimal point?) since the bullet it fires is about 25/100ths of an inch in diameter.
Internet searches, Blue Book of Gun Values, library, manufacturer of the weapon.