Ah, sorry...saw your question about separating the hub from the remaining shaft piece. I just use a pair of needle-nosed pliers, grip the shaft and carefully pry the hub off with a small screwdriver...working first one side and then the other. About the speedometer needle hubs, they're all the same with GM...at least for a multi-year span. I've attached 3 images. Two are showing a hub I made for a new needle a few years ago. When you buy the new needles, you don't get the hub to which it attaches. A bit of aluminum, some brass tubing and JB Weld are all you need to make a new one. I made this one to fit over a 1/16" piece of brass tubing. I could also have made it to fit over a 3/32" piece of brass tubing (what was used to recreate the original end piece) by using 1/8" OD brass tubing, but at that time I was planning on using this on custom unit I was making. In one image you'll see where it fits over the 1/16" OD tubing. And in another image, you'll see a hub from some other GM product showing the inside diameter of the portion that fits over the shaft is 1mm. Hope this helps. Those hubs are pretty easy to make. The trick is remembering your geometry well enough to find the center of a circle...
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end