I am sure 11m was not just a ham band in the USA. The USA may have lost 11m in 1958 but I many other countries such as Japan and South Africa continued to use it as a ham band for several years after. That could very well be the reason you will find 11m as a factory installed band after the USA gave it to CB'ers. I believe after that point you still had to cut a wire (or solder one in place) on the band switch to enable 11m in radios shipped to the USA.