I'm actually working on the 'vest' now. Pics to come later.
1: First you need one of the originals. If you look at it closely, you'll note that it was originally two bits that were glued together. Being very careful, you need to seperate the two pieces. I wasnt careful, and gouged my thumb doing it. (That's the accident I mentioned earlier)
2: Glue the new chest pieces onto the back of the old one. Theoretically the rubbery plastic on the back end should give enough flexibility you minimize flex on th resin.
3: In my particular case, the resin was warped a bit. I can force the vest to fit the chest, but it keeps popping out, and I'm afraid it'll put to much stress on the resin 'over the shoulder' bit. I need to soak it in hot water to make it a bit more malleable, and then 'set' it in the proper position.
4: I dont really trust the resin still, so I'm going to green stuff over the shoulders, since I need to fill in some bits anyways. I'm going to pin the back and front together as the only thing currently holding it on is superglue.