Hi folks,
Thank you very much for reassuring me on that little pitted area.
With the exception of the first 4 years, where I think I only used water, the last 21 years I have used 50/50 concentrate antifreeze + distilled water.
I cannot say what might have caused this, but after 25 years, I think she did well, and I hope she will continue that way
Thank you,
Alex