Cut a piece of aluminum from a beer can. Form it around the hinge pin. It is around .002-.003 thick. I used axle grease to hold it but better crazy glues might work if you clean the pin carefully. It is soft enough not to do damage. I don't know how long it will last but the price is right as long as you drink beer or even a coke.

Kutter's way is superior however more involved. If you just want to try out your gun and have fun the aluminum should get you started.

So many guns, so little time!