Good 22.
1956
1954-58
Between 1971-1973.
1956 570,813 shipped 7/21/1956
The JC Higgins Model 80 was actually made by High Standard for Sears, and is the same as the M101 Duramatic pistol. Made from 1957 through 1961/62. These can be bought on the use marked for $200-$250.
You can check the manufacturer's website for a manual on how to disassemble a High Standard Duramatic 101. Additionally, you may find detailed instructions in gunsmithing books or online forums specific to firearms. Always exercise caution and ensure the firearm is unloaded before disassembling it.
No way to know without trying.
Contact High Standard with the Serial Number and they will tell you when it was manufactured.
60-130 USD
100-1000 USD
1,000,000,000
Yes, they made that model