I believe the base is round. Also it appears the knob has been replaced by a smaller grip to turn it (or was that original). Found it on a magic lantern made in the 1920s. I also got it with a 15inch b&l Cooke triplet. Will be using both. Here is a pic of the CC Harrison. It seems like a 6 inch lens. What's the going rate for these????
CC Harrison lens
Thanks for your help guys!!!!
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