I know the difference between the makes of these water tanks, but am not clear on the water fill caps used. I have several of the Jno. Brown variety, but there are two styles of caps. What I think I have on there now is a Victor, but am not sure. It has a cork attached to a brass wire to indicate the water level. The vent has a bead around it, whereas the other one is plain, and the wire has a stop wire attached to it so the cap won't get lost. Trivia I know, but that is what I like!