On ec's hi hat,the down tube goes straight down,no curve to it,but still flat base...............is that unusual?
Nope, that's not unusual. That's how the 1121's were designed.
Model 1121 = Tube goes all the way to the flat base. Early ones had button feet. Later ones had slip-on rubber tips.
Model 1123 = Tube stops about 6" from floor, with a curved metal piece extending to the flat base. Pedal linkage is direct pull, into bottom of tube. Tilter screw added to cup.
Model 1123-1 = Mechanically the same as 1123, but with tripod leg configuration instead of a flat base.