To take apart the Gecado .25 caliber rifle, you will begin by making sure that the rifle is not loaded. Remove the retaining pin at the base of the barrel and remove the barrel.
Blue Book of Gun Values will help.
Small handgun
Inexpensive .25 automatic of indifferent quality. Values typically less than $100.
GECADO was a tradename of inexpensive handguns marketed by a firm in West Germany, mainly in the 1950s and 60s. The firearms were made by multiple other companies, typically in Eibar Spain. Values are typically in the $25-$75 range.
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
AFAIK, none. There were one or two importers in FL that sold 25 ACP pistols.
10-1000 USD depending on specifics
As long as it's the correct caliber, yes.