It is not possible to give you an estimate of value without more information about the condition of the pistol. You need to give it some sort of rating like Poor, Fair, Good, Very Good or Excellent condition. With out that minimum information I can not answer you.
This pistol was made between 1978 and 1984. Crosman no longer supplies parts for this model, But the offer a free service to locate shops that repair older Crosman air guns. See the link below
It was made between 1978-82. State the condition of the pistol to get an estimate of value. Is it still working? Rate it poor to excellent or like new?
The Model 761 made by Crosman was made between 1978 to 1981. It is no longer in production. Therefor no one has a new one for sale.
The Model 761XL was manufactures between 1978-81. It'd no longer on the market.
50-160
1978
Benjamin made a 137 pistol not a 137 rifle. They did make a 317 rifle, is this what you are asking about? The pistol model 137 was made between 1946-85 the rifle model 317 was made between 1940-1969
Model 177 Bullseye Target pistol They were made between 1957-1978
$450-$750
The Crosman model 788 BB Scout was made between 1978-90 depending on the variation. You need to state the current working condition of the rifle to get an estimate of value.
10 pumps = 580 FPS. made in 3 variations between 1968-1978
125 or so