Step 1: Parts and pieces
1 - Book holder. Barnes and Noble sold it for $12.95. It will hold paperback and hard cover books.
1 - 1/4-20 all thread bolt. I used a 5 inch long bolt but pick one that fits your stem.
4 - flat washers. Two sized to fit the bevel inside the stem, two sized to fit flush with the outside of the stem.
4 - 1/4 inch flat washers to help hold things together.
2 - 1/4 inch nuts.
1 - 1/4 inch lock nut to make sure it stays together.
All the hardware came from my neighborhood Ace hardware store.
1 - Dremel with a cut-off wheel and grinder bit.
1 - ratchet and socket(s) sized to fit your bolt and nuts.
1 - adjustable or combination wrench sized to fit your needs.
1 - bench grinder to speed up the correction of a marginal Dremel cut.
Total cost of parts: about $15.
Step 2: Prepping the stem.
After that, I used the Dremel with a grinder bit to put a small bevel on the inside of the stem to help the smaller flat washer center the post assembly.