A suggestion I was offered here was a similar nail board but rather than lie flat on a table the nail board is two pieces of plywood forming an L, with the nails in the vertical portion. Two columns of nails close together, a space, two more columns close together, a space, and so on as many nails and columns as you desire. The left column in each pair is labelled clip, the right column in each pair is labelled nib. Using 3/4" blue masking tape, I also labelled columns for the pen styles.
After removing the wax plugs from the tube-glued-in pen bodies, another suggestion I was offered here is to make a ring on the nib end of the lower body's tube with a colored sharpie (I use red), and a similar ring in the clip end of the upper body's tube with a different colored sharpie, (such as blue). Every time a pen body is handled, check the color coding and renew if needed. I turned and sanded the pen bodies in stages, marking the meeting end of the pen bodies with a pencil each time they were removed from the lathe, except after final sanding.
I was very happy with General Finishes' Wood about Finish on the last batch, applying it off the lathe with a folded bit of paper towel. I turned 3" of a 6" 3/8" dowel to fit inside the tube for each diameter I was using. Sliding a body onto the dowel, I held it by the last 1/2" at the fat end of the dowel and wiped finish on the majority of the body, rotating the dowel as I did so. After going around the body twice, I wiped the last half inch of the body into the fat part of the dowel, again going around twice. Taking advantage of the nails in a vertical piece of plywood, it was easy to carefully slide the body onto the correct nail using a fingernail without touching the wet finish. I was working on about 30 pens, a mix of Slimline, Elegant American, and Cigar, (three different pen tube diameters) and by the time I had applying a fresh coat of finish on the sixtieth pen body the first was dry and ready for another coat. After five or six coats I let them dry for an an hour, then level sanded on the lathe using 600 or 800 grit, can't remember, the finest grit appropriate. Then another 5 or six coats and repeat. Can't remember if I had to level sand a 2nd time, before working through the finest of the four sanding pads.
I completely assembled one pen at a time, again confirming the nib and clip ends with the color codes.