Charcoal Canister?
I don't know what they should sound like shaking them. They are difficult to take apart and service. It has been suggested to renew the activated charcoal by finding some at a pet store (I think the charcoal is used in aquarium filters). I guess you could duplicate the "screen" with any similar (or better) material.
The other question is this: What type of activated charcoal did Chrysler use in original equipment? There are probably different grades, calibers, processes, and maybe even additives used during production. I don't think any one is familiar with any "Mopar Guru" who would know the exact details.