fitting breathing mechanism

[treaclepudding]

hello people, ive been reborning for about a year and a half, but have only just fitted a breathing mechanism. fiddly little bliters, i had a sweat on i can tell you. has any one else fitted one. i found the upper chest area has to be left clear and unrestricted for the piston to work to its full capasity. also the preemie boddies were too small to fit one. what is your oppinion on them, with love treacle pudding x x x