At one time radiators did not develop a pronounced buildup in their cores. I have always been a little suspicious of the green antifreeze as the cause. In earlier times you ran water in the summer and winterized every fall with new antifreeeze. The radiators appeared to stay like new internally in comparison to later rads.
The concept of leaving anti freeze in year long eventually occured. That white buildup that also occured around the enterance to each tube might either be some component in the green antifreeze or a breakdown of that component.
For all I know whatever the agent was it may no longer be in the green antifreeze. This effect I observed on engines with even cast iron heads. My guess it was a byproduct of never changing the original anti freeze until the system broke a hose or something.
The coolant also must have swung to an acedic level eventually as well. I assume I should have a package of ph slips in my toolbox for occasional checking when owning so many cars. A baseline can be gathered simply by checking your latest fill. Probably does apply to any color of anti freeze.
Ph strips are probably a dime a dozen so to speak. I certainly am not a coolant expert. Come to think of it I have always wondered if a car in storage for a very long time should have the anti freeze drained or not.