Are you asking about the first Gun or Rifle? The first gun was made in 1935 it was part of the 100 series (100, 122, 177) the first rifle was made in 1899 (the St louis)
The first Benjamin model was the "St Louis model" made in 1899.
The model 340 was made between 1969-1986. I believe you have the first number wrong. I think the Serial number is T280984. If so it was made in 1977. See the link below for Benjamin dates. Crosman owns Benjamin and Sheridan air guns
All the Benjamin air pistols have wooden handle's. the first model was the 100 series (models 100, 122 & 177 made from 1935-41
Benjamin made several different pump air rifles. Please specify which one you are asking about. The model number will most likely be on the barrel.
The model 100 was made between 1935-1941.
If you are asking about the Benjamin Air gun model 342? It was made between 1969-1992
They were made between 1938 to 1941
It was made in 1967
It was made in 1960
It was made in 1965
It was made in 1969.
Benjamin made a model 1300 air pistol not a air rifle. It would be worth between $130-$155 in VG shape They were made between 1959-1964 They did make a 3100 air rifle... If you have a 1300 rifle then I do not know the value.....