Would you share your experience on how to make them?
I'll tell you my experience from just yesterday...it was a nightmare. John's some kind of cork magician, I'll tell you that much!
I tried a couple of things, and with enough practice I think I could pull off a poorly executed version of what he's posted. First off, it would be simple enough to drill a cork, swather some CA on a brass tube and cram it in. Problem is, the resulting blank is going to need to be turned down. There goes the labeling.
Then I tried making a veneer out of the cork by first drilling the largest hole in the cork I could manage and then cutting the cylinder lengthwise with an Exacto knife. Then I soaked the cork in warm water and put it in a crude press to try to flatten it. With a bit more patience, I could have got a reasonably flat bit o' cork to work with. Problem is, you've still got to thin it down. A surface plate and some wet sandpaper would work if a guy were patient enough, though again, you can obviously only thin the inside or the pretty (I'm guessing pyro/burned) artwork will sand right off.
Then there's the issue of the resulting veneer being too long to wrap perfectly around the tube...or too short. Too short and you're out of luck. Too long, and you MIGHT be able to trim it down. And if you're lucky, you just might find a visually acceptable way to get rid of some of the label.
Then there's the issue of how to cut off the extra. You COULD overlap and use an Exacto to cut through both layers at once, thus ensuring a smooth cut that will match up, which I'm guessing is the best way to handle this chore.
Then you have to glue the darned cork to the tube! And line it all up. I tried zip ties to act as band clamps which caused the cork to pucker at the seam. I think maybe extreme patience is the only thing that would work to get it done right if the veneer route is taken.
If all that works, you still have to get a finish on top of it. I'm guessing BLO and CA would work well enough.
Bottom line...the man is a cork wizard of some sort as I mentioned at the start.
LOTS and LOTS of frustration TRYING to make a cork pen blank. LOTS.
My hat's off to John!
-Matt