The Marksman doesn't require much cleaning. I suggest you purchase Crosman pellgun oil and put some on a cloth and wipe down the pistol.
Open the breech (Barrel) put a drop of oil on a q-tip and run it through the barrel. Do this until the Q-tip is clean.
DO NOT use any firearms cleaning agents on the pistol or it will ruin the seals in the gun.
which Model are you asking about
go on the computer and scan the words 'marksman air pistol' ...............
To get an answer you will have to state the condition of the pistol & is it still working?
Gamo Hunter Extreme 1650 FPS - Air rifle .177 Cal Air Force TalonP 900 FPS air pistol .25 Cal Hatsan AT P1 Air Pistol .177 870 FPS The Air Force TalonP is faster in .25 Cal than the Hatsan .177 Cal
Starting in 1977 to present
Marksman doesn't list the cocking effort but believe me it's very little. The pistol only fires a 220 FPS and that is slow.
200 Feet Per Second (FPS)
This is a .22 caliber air pistol not a .177 caliber pistol. See the link below for the owners manual.
There's a double action to the slide - see the link below for a manual:
No-one seem to have a diagram on the repeater but I did find this on the web. see the link below
somewhere around $30
That would most likely be the Hatsan AT P2 PCP Air Pistol at 870 FPS