Crosman MKII

I recently purchased a number of old airguns. In the lot of guns, I got an MKII pistol. I did put a co2 cart in it but it is leaking from the valve. I ordered a rebuild kit and am curious if anyone knows of any mods that could or possibly should be done while I have it apart?

I also have both a 115 and 116 with the original co2 bottle. Where can I get an adapter to either use a new co2 bottle to fill the guns or an adapter to be able to fill the original bottle?

Thanks
Aaron
 
Got the MKII all back together with the new Mac1 parts and a factory original hammer spring from JG Airguns. Gun went back together without a problem. Shooting .177 polymags, I was getting 470fps. Not sure of the shot count, but was at 25 and the gun hadn't started to drop. These MK'S are such nice pistols with good triggers and good accuracy. This has me thinking about ordering an LD!!