Nice Pens, Donald, (Thanks for the Photographs and not the Thumb Links)
Nice Fit, but I notice that you have some Dark Staining coming from your Bushes, into the Blanks.
This is usually metal particles coming from the Bushes during Sanding.
It can be lessened by sealing the end of the Blank, after you have taken it down to the Tube.
Some CA would do fine, just take care not to get it into the Tube, or if you do, then clean it out before you assemble the Pen.
Are you wet sanding?
Regards,
Brian.