Hi Lou,
In the early 80's, the largest water bottles were 22 oz. Many of the early Columbines I sold had over and under on the DT and occasionally on the seatube as well. After the advent of larger water bottles, only the touring bikes got an under DT boss, which could be used for fuel for a cook stove as well as water. What are the specs and serial Number on this bike, I might have sold it new. Some of the bikes that came back for repaint that had pump on the seat tube and over/under bottles on the DT got a pump peg on the headtube and a set of boss mounts on the seattube. This might also explain it. My new polished SS Columbine should be here shortly. I can hardly wait!
Paul Brown
Cycle Dynamics
Santa Rosa, CA