Gents, I am reporting back as promised. I used oxalic acid dissolved in warm water, not sure of the concentration but it was 1 teaspoon in about 1/4 cup of water. I applied it several times with a Q-tip, let it sit between applications and then neutralized with a solution of borax. Of course I wore protective gloves. Also applied one light coat of stain last night and here's what I have this morning. Thanks again everyone for your inputs. Next step is to chase the border checkering.
Just as an aside, the oxalic acid arrived in a plastic zip bag with no MSDS, no Caution sheet, no nothin. I love it! Reminds me of when I was a kid and was able to buy chemicals pretty freely, and the supplier assumed you were a responsible person. Frank