This answer to Saturn V Small Rectangles On S-II Stage includes images and links related to the Saturn IB rocket. It shows what I think is an unwrapped representation of part of a circumference which proceeds from Fin 4, 5, 6, 7, 8, and then Fin 1.
Question: Did the Saturn IB have eight equally spaced fins around its circumference? If not what is it that this drawing is showing?
Indiscriminately cropped from here; [Source] APOLLO/SATURN CONSOLIDATED INSTRUMENTATION PLAN FOR AS-204/LM-1 pp 3-5 & 3-6