see the link below for the owners manual. The Marksman Repeater is a 4.5 .177 caliber pistol not a 5.5 .22 caliber pistol.
.177 cal. Crosman, daisy, rws, beeman, marksman all make pellets in the .177 size
go to the link below.
Made by who? If you are asking about a Marksman Repeater, then it is not worth much. They only cost around $20 brand new. Used they go for less that $10
In Good condition it would be worth around $10. (Bluebook of Airguns 9 edition)
which Model are you asking about
It's in the grip. See the link below.
It was made between 1976 and 1983.
Lets start with: Who made it. How old is it. Is it still working. What do you mean by "USED" Well Used or just used.
Your best bet is to go on-line and do a search for "Airgun repair" and locate a shop near you for repairs.
It would be worth between $80 - $100 in good condition.
This is known as the repeatAIR not repeater. It's the Crosman model 1008 You can find the parts diagram for all Crosman's weapons on their web page. (See the related link at the bottom of this page) then click on Rifles or Pistol manuals