Plo Koon didn't have a lightsaber in Episode I.
I assume you're looking at the one on thelightsaber.com which is something Luuke made based on the tiny action figure accessory. You'd have to ask him how many grips he put on it.
From what I remember working on it (did a bunch of work for Jedi135, trying to measure it out, back when he sold them), it had 8. But it was just a saber design extrapolated from the artwork that came with the Plo Koon 3" action figure, back when they came with those cheesy "tech specs".
That saber was ANOTHER one of my project ideas that Tim got credit for. :rolleyes