Success! By using the Schneider controller powered by a lab power supply I got hydrometer readings in the green for all six cells. This was after charging and equalizing.
The controller is a Xantrex C35 PWM type. It can be set up for different charging profiles so it is pretty ideal for atypical batteries. But of course it doesn't work if the power supply has a bad connection.
So I'm good to go as long as I am using the solar panels. Not so sure about the charge system in the camper though. Apparently the voltage isn't high enough for the T-1275.
Thanks so much for the advice!