You might look at current practice for STI types which is to braze cable stops on the side of the
head tube or the down tube adjacent to the head tube. Original practice was to have the cable
stops 6-10" down the down tube in the same place as downtube shifters were mounted and to
have an adjustable screw there also but this practice was abandoned in favor of the head tube
or near head tube mounts with no or simplified adjusters. There are water bottle mounts that
only need a hole in the tube into which the mount is placed and it locks itself into place. No brazing
needed. Steve