I may have an answer for you. While doing some research on the Hercules air rifle I had trouble locating it in my catalogue. Then I realized that Hercules was the maker of the arcade game with rifles. Not the rifles name or maker. It was then that I realized that Crosman once made Air Rifles for arcades. The Model 102 "Camp Perry" introduced in 1931 used a hose attached to a C02 tank and was used only as part of an arcade gallery. I think this is your rifle. The Maker may have their name on the rifle to verify this. It looks very similar to a Crosman model 101 except it has a hose right in the bottom middle of the rifle. It also has a wooden stock and forearm. The Barrel looks like 2 barrels one on top of the other.
it was made in 1975
you need to state the model number not the serial number to get and estimate of value.
Model number, serial number and features. Then ask that question again here with that information.
If not marked, you will have to check features against old catalogs
T427432 was made in 1982.
It depends on the model, but it usually is on the barrel somewhere or the breech below where you load the pellet or BB.
This model was made between 1969 to 1992. The serial number indicates it was made sometime after 1982.
If it's not on the outside then very possibly it's under the grip cover
1980 see the link below. See the link for your date of manufacture
It depends on the model, but usually it is right on the barrel or the receiver. If it is really old it may not have a serial number. For a time Benjamin and Sheridan did not serialise their rifles.
It was made by Iver Johnson after their Champion Model for Montgomery Ward
10-100 usd