There's been a lot of discussion about this over time. The dealers did the mirror installation here on the early 105's, so, there was some differences in location and style. Having said that, the round mirrors were generally used up to and including the 1969 model year. The U.S. didn't get any 1970's officially and when the kamn tail came in they had the trapezoid mirrors. There probably were some '71 1750's with round mirrors and I had one guy tell me his '69 came with a trapezoid mirror. I'm sure some of the guys with long term ownership can chime in with first hand knowledge.