The check valve was usually a small ball bearing that was confined in the removable brass fitting that was screwed into the air outlet from the cylinder. It was confined by slightly crimping or deforming the barb at the outlet. The pump piston is made of leather and can be made out of an old shoe toung. Grease lightly with cup grease, do not oil. The part that screws on the tire valve has a projection to depress the schrader valve. On some models a check valve was located behind the depresser. Good luck, Art