The tall tanks were offered from 1949 through sometime in late 1951. The Johnson QD and SD motors used them and the Evinrude 14hp Fastwin used them. Some interesting features are the diaphragm being smaller and located low down rather than in the housing like the later tanks, the magnetic Rochester fuel gauge and the pressure shut-off valve on the "fuel out" line. While parts are not available (that I know of) you can make the diaphragm and gasket from bulk material.
There was also a second tank that resembled the "tall boy" tanks but had the more typical design and diaphragm. These were only offered for a short time (late 1951 into 52 if I recall) before the rim was removed.
