Ingersoll Rand Quiet Impact

[Ruger10/22]

hello all, longtime reader, first post
I recently got an IR 2135TiMAX for next to nothing. It needs a rebuild and I was wondering if I could make it into a 2135Q without too much trouble. Marlin posted "The Quiet technology consists of 4 additional parts, the foam piece that is visible (in the handle) is only one of them". Does anyone know what the other three parts are?

 

[stikman56]

There's a thick felt like piece that goes around the motor cylinder, those are the only two things I have ever seen having them apart as compared to the non quiet versions.