50s style recurves were rather plain and simple usually with plain maple risers. 60s recurves started to exhibit exotic woods like rosewood, bubinga, shedua, and designs with small horns in the risers. There wasn't much difference in the early 70s outside of the exotic woods were dissappearing and new composite woods like "actionwood" started to appear. The designs were similar to 60s bows.
I'm short of time or I'd include some photos. Perhaps later today. I realize I oversimplified the explanation.