First, thanks everyone for the help.
Second, Old-Biscuit - Thanks for the service manual. I had only "Literature number 52229' that came with the camper. It left a lot to be desired.
Third, a glance at the service manual shows I was wrong about something. I thought there are 3 gas lines and one thermocouple coming from the control. The lines 'look' like that but the service manual, and a little thought, reveal that to be wrong. There are 2 gas lines and 2 thermo lines - except it sure looked like 3 and 1 when I swapped control units.
4) I'll get back on it tomorrow.