Hello,
That looks great. A couple questions:
-Is that sized to fit a rollerball as well?
No. It would have been a simple matter to do, but the buyer was dead set on a fountain, so when I asked him if he wanted it to be "convertable" he said "no."
If so what is the length of the cap and body?
As I said, it would have been simple enough to do. The outer length of the pen (with nib) was 5.8 inches. He has long fingers and wanted it long. The cap is only a quarter of an inch longer than a Gent Junior cap would be. The inner holes of the pen would be as follows: For the rollerball spring, drill a 9/32 diameter hole 2.8 inches deep. Then drill the tube diameter hole to proper tube length (Just off the top of my head, I think it's 1.9 inches. No wait, that's the cap hole. 2.1 for the pen barrel tube, I think. Check with your micrometer.)
-Did you drill the holes the same size throughout the body and cap or "stairstep" them?
I drill on the lathe for accuracy. I start with a perfectly squared up blank. Then a center punch for a precise center hole. Then "stairstep," if that means what I think that means.
-Also, have you figured out how to put a clip on that?
Sort of. The way I have done clips on these closed end jobs involved cutting the cap, so really the cap is not a closed end. I have several ideas in mind on how do do it with the cap as a true closed end, most of which involve drilling very small holes and using small screws to hold the clip in place. But coming up with the clip itself is still something I have to work out.