The American Gun Co. firearms were made by the H & D Folsom/Crescent Arms Co. in the very late 1800's thru the early 1930's. This organization manufactured low cost firearms under a number of different names. You could actually buy the same firearm at a number of different stores with different names on it. These were relatively low cost, but servicable, firearms. Most of these guns were not only used, but used hard. As such, they are usually given a value of about $200 assuming that they a useably condition. If the firearm is in very good condition it could bring 2 to 3 times as much.
50-150 USD
Seldom exceed 100 USD
Pretty much an impossible undertaking.
50-100 USD or so
Why would you want to buy a gun?
10-100 USD or so
50-100 USD
try numrich gun parts
50-150 USD
You might try Numrich (e-gunparts.com). If your Knickerbocker was made by Crescent, they can probably help, but if you have a Belgian-made gun probably not.
50-150 USD
less than 200. They were just a hardware store gun. I found one resently in my grandfathers atictc and was pretty disapointed that it's at most only worth 200 bucks. But its pretty dam cool looking.