I have no idea (and neither does anyone I know of-even in the Bond community) as to the origin of the alternate audio but my guess would be a test 70mm mix or perhaps differences between UK and US audio mixes on the original release.
As a Pre teen and teenager I had seen the 1 st 3 of the Connery Bond movies during their original runs at the Theater. I seriously doubt that Dr. No had a 70mm mix. The Theater I saw the 1st 3 movies had 70 MM capabilities. I Saw Exoudus in 70MM there. I doubt DN had even tested any 70mm footage as that films budget was very tight. It was never expected to be a big film. They Milked that movie for all it was worth by the time Goldfinger had come out. The theaters in America had routinely run DN & FRWL Saturday Matinee double features. They even showed them during the kids matinee in my town, 6 RC cola bottle caps would get you in. This was before the rating systems.
Just my 2 cents worth.