While I don't know your particular unit my 77 magic chef uses a mercury flame sensor. These can be confused with thermocouples as they look similar and performed the same function. Mercury flame sensors contain mercury and a decent amount of it) that heats up if there is a lit pilot and causes the main gas valve to open up. If your unit was damaged, the mercury may have leaked out
Mercury fumes are a significant health hazard. A google image search provides a fair amount of examples of MFS's although mine was a bit harder to find. If the mercury leaked out you have a real problem.
I'm not sure what to do if it has, but I would not want to be in the trailer.