Most early american bikes had the foot clutch with the shifter on the tank. You controlled the ignition advance with the left grip, throttle on the right(duh)... And the earlier models had a manual oil pump... as you were going down the road you would push a little button on the tank(one half gas, other half oil) to pump the oil in. The first Knuckleheads didnt have valve covers and would spray oil all over your pants going down the road!!!
And riding like that is ridiculously unsettling. You feel like you have zero control. Thats why I like my inline fours, they're made to ride not just to look cool! That being said, I think that was a zero engineering bike. If I HAD TO have a custom HD, they'd be building it. They started restoring old 45in flatheads and hoppin them up. Look em up, they do some cool stuff!