This pistol was made between 1971 to 1980. I am unable to place an estimate of value. Because you gave no description of the pistols condition. Without more information it is not possible to answer your question
Any good sized air gun shop should be able to help
Try a large well stocked air gun shop.
Contact S&W
I have rebuilt these with o-rings from the hardware store and they work great.
It's going to take some searching. I would contact several of the places that I have listed on the link below. Or do a search for "air gun parts" on the web
S&W made a 22 pellet pistol model 78G from 1971 to 80 later it became the Daisy model 780. In order to give an estimate of value I need to know more about the pistol. Like the current condition and is it still working? Is is in Poor, Fair, Good, Very Good or Excellent condition? Without more information it is not possible to give a fair estimate of value.
The S&W 78G has not been made in a long time. It was made between 1971-80. I suggest you check the web under "Airgun Repair" and contact the shops you find, ( I was able to locate a set of grips for an old Crosman 38 this way.) But it may take a few calls to locate a set.
Do a search on the web for "Air gun repair" and locate a shop near you to repair the air gun, or See the link below.
I would do a search on the web for "Air Gun Repair," there are shops that make a living repairing air guns. Or see the link below.
During the 1970's Daisy bought the rights to S&W airguns they renamed the 78G and 79G to 780 and 790. You may want to contact Daisy Airguns and ask them for a diagram. see link below.
The mass of the pickles and juice inside the jar is 172g (250g - 78g).
78g = 2.75oz