The analysis of Calvin Peete's golf swing above by professional instructor Jim McLean shows a solid swing with very few unusual components.
Jim McLean points out a couple of differences with the modern swing: (1) Peete's head does not stay centered but moves both downward and forward during the swing and (2) Peete's leg drive (the solid yellow lines are his original leg locations at address) and forward motion are stronger than the modern player. Peete also did not maintain club head lag deep into the downswing. Typically, instructors want to see the club at the dashed yellow line halfway into the downswing. Peete's club has released to the solid red line. Peete was playing with persimmon woods and balata-covered golf balls which may have required a different swing. My remembrance is that Peete did not have a lot of length off the tee. What he lacked in distance, he made up for in accuracy and obviously he was able to hit the ball long enough to compete on the PGA Tour at the time.
Calvin Peete was one of the great, unique, self-taught golfers on the early PGA Tour. It was honor for me to have seen him play in his prime.