hey Micheal!
I dont have such a gun to try it out but I do have a few suggestions in such cases;
1) since you say the carriage is easily replaceable...although its quite an ardous task (not for me really), I'll rather cut/file/drill down the insides of the carriage
2) or cut/file down, btw I just bought an Ozito set (cheap australian hobbyist rotary tool)

the pins & collar of the gun
3) something I thought off long ago but still dont have to do....file off the teeth of my pliers...then add the felt like AndrewL suggested
oh..almost forgot....I like your customs! not just the guns
