Do you mind sharing how you made the spirals?!?!
Glycerine:
I processed the bubinga blanks just like normal and turned them until they were maybe 1/64 oversize. I used a Beall Pen Wizard to cut the spirals with a 1/8" flat bottom bit. Groove depth was a few thousandeths below the oversize blank. You have to allow some margin as setting depth on the Pen Wizard is not really an exact science. The maple/ebony inlay strips were glued into the spiral grooves. They were only about 1/32 thick so they had enough flex to be forced into the spiral and then held with lots of rubber bands and clamps until the glue dried.
I tried six grooves but thought it was too busy and four was too plain. I ended up making my own index plate for the Pen Wizard to give 72 degree spacing and cut five spirals.
There isn't a lot of figure or obvious grain in the bubinga (most of it is away from the camera), but after cutting the inlays in the bottom of the pen, I matched the top blank grain to the bottom and marked the edge of the first spiral. By using that starting point, I was able to end up with both the grain and the spirals matching between the two halves.
Once the inlays were set, I put it back on the lathe and took it all down to the final diameter. Finish was a whole bunch of coats of Tru Oil gun stock finish.