Usually in Deathrun you buy a few player models a trail or two and that's pretty much it. It would be kind of nice to add in something else for players to buy.
This is a great suggestion and could benefit the server; however, there are a few minor issues in my opinion. First, you have models that are different sizes, and you would have to program the accessory so that it fits on all models. Additionally, how would the accessory look when player's are bhopping? These are just a few factors to take into account. +1
I believe it works the same way as trails do from my understanding. I could be wrong though. but yes, like vector said, it finds the skeleton of the model and assigns the hat or whatever to the correct bodygroup.