Hi,
I don't have an answer, I wish I did! I have just struck the same thing, ripped up an entire house full of carpet to find great floorboards in the whole house except the hallway, which has lino glued on top of the boards. Like you, I am finding the glue hard to remove but I want to keep the matching floorboards in place if I can.
Did you find any tips at all in how to remove the glue residue (black, right?) before you did away with your floor?
Any help would be great and good luck!
Felicity
Felicity, May 2008