Sorry to post this because I know the info is on here somewhere, but I'm not having any luck finding it.

I'd like to find the part number for the plastic sleeve part of the throttle control that one would glue a grip to. Just a simple link to where I could look would be great, I don't mind doing the searching. Thanks in advance!
The reason is that I can't get these old grips off. So, alternatively, I wouldn't mind advice on how to get these damn things off. They're metal with no visible screws of any kind to remove. If they were rubber I would just cut them off.
They look very similar to these:

The black lines on them seem to be part of an internal rubber grip. I can only assume that these come in two pieces and you would glue on the rubber grip, then press the chrome housing over top of it until the rubber part pops out through the slots, making them seemingly impossible to remove from my perspective.