The model 117 is part of the 110 series of Benjamin airguns. It included models 110, 112 and 117 they were made between 1938-1941. In order to get an estimate of value you need to state the condition of the gun. From Excellent to Poor and is it still working. If you would like a copy of the owners manual see the link below. Today Crosman owns Benjamin airguns.
This is a .22 caliber air pistol not a .177 caliber pistol. See the link below for the owners manual.
it would be worth between $45 and $65.
Most all C02 air guns use the common 12 gram C02 cartrage.
It was made in 1976. It's part of a series of 3 pistols (130 Series). It's either a 130 - BB, a 132 - .22 cal or a 137 - .177 cal pistol.
This is the best I can do. (see the link below)
Auction
Which Model are you asking about.
This is a .22 caliber air pistol not a .177 caliber pistol. See the link below for the owners manual.
It started in 1946 to 1985
it would be worth between $45 and $65.
The model 100 was made between 1935-1941.
Benjamin made this model from 1946 to 1985, but did not start serializing them until 1957. I also have a Benjamin Franklin that has no serial number. Before 1957 it is not possible to set an exact date. Just know it's OLD. The 137 is a .177 caliber pellet pistol the 132 is a .22 caliber pistol and the 130 is a BB pistol.
Most all C02 air guns use the common 12 gram C02 cartrage.
It is very rare to find a model 117 in Excellent condition. It must have NO wear, scratches or dings. In Excellent condition it is worth around $150 it was made between 1938-1941
Between $50 - $65, Add 10% for wooden grips, add 30% for Black nickel
I suggest you try this web page. BTW Crosman owns both Benjamin and Sheridan air gun products. You can also contact Crosman and ask for help.https://support.crosman.com/hc/en-us/sections/200649600-Benjamin-and-Sheridan-Air-Pistols
Not desgined to do this