Have it checked by a gunsmith.
http://www.tm-techmark.com/jspacek.htm - This site specializes in High Standard.
50-140
Made for Sears by High Standard, and is a version of the Double-Nine revolver.
22-72
S&w
Smith and Wesson Model 1
All of them have a sn.
A .22 caliber Iver-Johnson Cadet revolver.
Impossible to answer without knowing who made it.
300-500
Made by High Standard and is a version of their Sentinel revolver. www.countrygunsmith.net