Throttle grip


Here's the dilly...
I want to make some custom grips utilizing a 2 part
First is the Aluminum under grip that contains the  
inner palm flange and outer palm flange, then using a piece of this rubber tubing from work that's perfect for a grip, I'll place the rubber over the aluminum sub grip.
Then whenever I have to change my grips, I grab a couple free pieces of rubber, cut the old ones off and slide a new chunk on with some adhesive.
Problem comes on the throttle side.
The white plastic portion under the grip that "is" the throttle.  How does this piece connect inside the plastic throttle housing on the handlebar?  Without ripping mine apart right now, is this a fairly simple operation of dismantling the housing?
I think if it's a fairly straight forward connection, I can Machine the Aluminum sub-grip and the throttle connection all as one piece.  Perhaps have a roller bearing pocket under the sub-grip on the end for increased smoothness.  
Anyone have a spare throttle kickin around?
I know it's hard to visualize...maybe I'll mock up a sketch.

If you look in the first pic the starter switch housing rides in the groove, holding it from moving in or out. Then the two cables attach at the end.