I seem to recall seeing pictures on Wikipedia years ago that purported to be stone smoking pipes from ancient Britain or something. Now I can find nothing on this. Presumably because it contradicts the general idea that smoking wasn't "discovered" until the New World.
People smoked hemp in ancient times whether you believe it or not, so why is the evidence all hush-hush??
Can't help, but I'd recommend cross-posting to r/askanthropology