I asked the maker of the mosaic pins what the best way would be to work with these things. He said to use a Dremel tool with a cut-off wheel to cut the pins to the lenth I wanted. He emphasized that using a hack saw might damage the pins. Apparently these things are more fragile than they look. The varying hardness of the different materials used to construct the pins would cause the saw blade to drag and maybe damage them. I suspect that gently using a saw with a very fine toothed blade might be okay, but I did follow his recommendation. He also cautioned me to be very careful not to get the pins too hot as excessive heat could cause the epoxy to break down.
Before the gluing process, I cut the pins to extend about 3/8 inch on both sides of the handle knowing that I would be sanding the whole thing down to the proper size.
After waiting about a week to make sure the glue had seasoned well, I used the belt sander (carefully!!!!) to grind down the pins to the level of the handle material. The micarta slabs were a little thicker than I wanted so I used the sander on both sides until I had it to where I wanted it. I was careful; I used the sander gently and made sure to let the everything cool off before the heat built up.
I used the belt sander (gently!!!) and the Dremel tool with a sanding drum to remove the excess handle material and progressively finer grades of sand paper to finish it off and bring it to a final polish.
Patience is everything in a project like this. It is very easy to take too much off, and you can't put it back! Belt sanders are powerful tools and it's very easy to press a little too hard and ruin the entire project. Believe me, I know this from previous experience!
It was a fun project. I don't know if I will try this again, but I did get some Antique Gold paper micarta from Ken Davis recently and I may just have to do something with it.

- - - - -Buckspen