My husband and I own a 1993 Pace Arrow.  We are looking to replace the shroud on one of the air conditioning units.  The information I do know is this:  ColemanTSR is seen inside the coach on the AC unit where the selector knobs are located for on/off, settings for high/lower, etc.  The current shroud says "Mach".    This air conditioner is probably original to the motorhome in 1993. 

How can I determine the Serial Number or Model # for this air conditioner?  This information has faded off of the data plate.  I want to be sure to order the correct replacement.  Thank you for your help! 

Peggy