The chassis is very brittle ...you really have to be extremely careful what solvents, glues, and greases touch that plastic.

Brake Cleaner can now be added to the list of no no's for the Tamiya plastic chassis.
Also NEVER use any threadlock as it too will make the plastic break apart (i learned the hard way). By the way, I was using threadlock on a metal to metal piece but some of the thread lock seeped onto the plastic ...all it took was a fraction of a drop.

sorry for your lose, yet the good news is a complete chassis can be had for about $12!