[khgeisler]

Brass key is coolant access door. Silver keys are bay doors.

Richard,
Yep, My tumbler is CH545 as well.  Did not see it at first, but once I saw it on your key, I recognized the number from my searches and looked at my tumbler a littler harder.  There it was barely legible thru the paint.  I can buy the tumbler and the key from austinhardware.com as mentioned above, just cannot seem to find the cam setup that we have.  I will search thru the 25 extra keys I got with the coach and sniff out the ch545 and the keys that look like your radiator key.  Once I have the key locks working, then I can work on the few power locks that do not work.  Just have to figure out the long rod configuration issue.  The new ones come with shorter rods.

Thanks for your help!!