Attached is picture of the “land” of the cylinder head . It’s approximately 0.024-0.030. Is this “land” dictate how much more can be shaved off the cylinder head surface before it needs to replaced?
Maybe...and it depends. You usually can mill the head .030 to maybe around .040" but that assumes it hasn't been milled before. I always stop when the least amount of milling produces a flat surface. Not good to go too far and today you can not easily find the thicker (and in my opinion better) copper sandwich head gaskets. The ones you get today will be thinner.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end