First of all I would NOT go sanding down any large peices of carbon fibre, 1st because the dust particles created is really bad for your lungs and secondly it will go dull and you'll never get it back to looking like new.
As suggested if you want like new it would be best to buy new, if you relly want the chassis to really good then your best buying a new one. There are a couple of sites that offer new chassis for various cars I would try exotek.
I would definately glue the edges, not sure what glue is doing on the main part of the chassis if they haven't glued the edges
Maybe he glued his tires whilst on the the car?