684s:
Pump cylinder height in the bowl is approximately half-way from the floor of the bowl to the top of the bowl.
Accelerator pump skirt is at the bottom of the pump.
Pump return spring is above the pump (between the skirt and the bowl cover)
574s:
Pump cylinder top is flush with the top of the bowl.
Accelerator pump has metal cup below the leather skirt to hold the pump return spring.
Pump return spring is located below the pump (between the pump skirt and the bottom of the pump cylinder.
And (no offense meant) while "a picture may be worth a thousand words", it also takes 100 times longer!
Jon.
