Thanks for responses. I had been forming the opinion that I had to go down the customised road, in which case for me will be the road of least resistance.
Given kj7e's example, and a son with a strong python background, and a target that only covers specific datalogging using the 010 20-channel mux option for a simple setup of a few LM399 and REF102 voltage references and local temps, it's looking like that is the road I will take for the legacy 3497A device.