That is sort of like "How much can you sell a car for?". Depends on the car. The least I have ever paid for a .22 rifle was $10- the most about $1000. Those were two VERY different rifles, in different condition.
22 hornet is a 22 calibre rifle. Most think of a 22 rifle as a rim fire rifle. But it shoots a 22 calibre bullet but the cartridge case that fires the bullet is no where near the same. The Hornet holds much more powder and is center fire.
A LOT
$75-$125
$12.57 From what i have read, one in fair condition can sell for about $150 and one in good condition can bring as much as $250.
it is 56 Remington rifle model
1938-1945. These dont sell for much, typically under $100. sales@countrygunsmith.net
These sell for between $350-$450. NO- 22 LR ammo cannot safely be fired in a .22 magnum rifle. The .22 magnum case is larger in diameter as well as longer. The .22 LR cartridge case will split.
It all depends on who made the air rifle and the power plant that the rifle uses.
You will need to contact the State Police
Your rifle was made by Savage/ Stevens/ Springfield. Depending on condition, they sell for around $125.
Depending on condition, about the same as any Marlin 70 rifle.