If you're looking for a metal ring to fit inside the gem area, this is what I'm using:
You can see the ring from the pen fits the gem from Michaels EXACTLY. In fact, the gem has a slight taper, so the ring will not fall past the gem. If you glue the gem to the metal ring, you can glue the metal ring to the indent of the ring and it will fit exactly. This also gives you a bit more room to work with for fitting electronics under the gem.
The pen is a Sanford "Expresso" medium felt tip pen. My father works at an advertising firm, and I've been using these pens since I was little to draw, so they've been around a while. I tried looking them up online, and it looks like the current revision comes in a similar style, however it seems they've phased out the metal ring.
I just got off the phone with my dad and he says he might have boxes of these pens at work still, and he also says that whenever one goes dry, he saves the metal ring off of it, and thinks he might have a couple film canisters in his desk at work full of them. (I have no idea why he would do that, but thats my pop.) He'll call me tomorrow and let me know if he has any left. Anyone interested?

You can see the ring from the pen fits the gem from Michaels EXACTLY. In fact, the gem has a slight taper, so the ring will not fall past the gem. If you glue the gem to the metal ring, you can glue the metal ring to the indent of the ring and it will fit exactly. This also gives you a bit more room to work with for fitting electronics under the gem.

The pen is a Sanford "Expresso" medium felt tip pen. My father works at an advertising firm, and I've been using these pens since I was little to draw, so they've been around a while. I tried looking them up online, and it looks like the current revision comes in a similar style, however it seems they've phased out the metal ring.
I just got off the phone with my dad and he says he might have boxes of these pens at work still, and he also says that whenever one goes dry, he saves the metal ring off of it, and thinks he might have a couple film canisters in his desk at work full of them. (I have no idea why he would do that, but thats my pop.) He'll call me tomorrow and let me know if he has any left. Anyone interested?