Thanks all...
Gasman... I would have to trace the lines out to be sure but I suspect the LP generator is the reason for the second regulator or as gmelton suggessts the water heater and furnace (or all three).
If I could put in a tee on the line to the generator that would be prefect as it is right where I want to put the quick disconnect for the grill(s). I do plan to add a cutoff valve (thanks gmelton).
dewey, you are correct the second one is for a Coleman (an LX, not LXE - different color and different stand but the same otherwise). The other is a Primus Profile. Thanks for the video, I had no idea the Coleman was propritaty connection. I hadn't tried it but I just assumed that the connection to the actual grill was the same for both of my grills. Knowing it isn't is helpful. I'll just plan on setting up the Coleman as the video shows and leave the other one at home.
Now I just have to find out the pressure going to the Onan Microlite 3.6 generator and then figure out if that is appropriate for the grill.