All three of these models have identical single stroke pneumatic actions. The 753 has Gamo match sights, pistol grip stock and Lothar Walther barrel. The 853 is a more basic version with Daisy aperture target sights, straight stock and Lothar Walther barrel. Introduced in 2004, the 953 is a budget version with open sights, synthetic pistol grip stock and generic barrel.
These instructions suit both 753 (Gamo) and 853 (Daisy) rear sights:
Clockwise up.
Clockwise right.