Here's 2 more of mine. The 86 with aero bars Is my exact size and my back is relatively flat when in the aero position. In contrast the 88 built to ride with a group/club rides has a smaller frame and ridden mostly on the hoods. Currently it has big pink pedals and a coupling on the non drive side to attach my 3 year olds baby's trailer. You can see more pics on the vintage sales thread.
I'll be 55 this year, however I've been stretching almost my whole life, but I think our body's can adapt to just about anything.