OK... here is what you do....

1-get a dowel the same diameter as the inside diameter of the smallest post you can find.
2-drill a small hole 1/4 inch from the bottom of the post all the way through both walls of the post (these
will be way down in the seat tube when installed)
3-mill down end of the dowel to something that will fit in the chuck of a drill press.. most likely 1/2"
4-insert fat part of dowel into bottom of seat post, and put two screws into the holes you drilled. (predrill
first)
5-chuck it up and set the drill press to a vert low speed (or you will die) and apply a file or sand paper to it while spinning, check with calipers occasionally.
6-when you get close step down on sand paper till you get to about 1000, and it will look good.

trick is to ever so slightly taper it in at the top, or you could create a small step.

good luck, BWAHAHAHAHA.



remember SLOW SPEED.