I completely forgot to show you how I was finding each position to machine because I got into high gear once I got started. So let me explain: Pretend that those metal dowel pins are in the holes that I put in at the beginning. I touched the outside of the pin with my indicator, set my zero, then moved to the other dowel pin to see if I needed to make any adjustments, because they both need to be in alignment.
 

Once I moved my table to the other pin and it showed me that I needed some adjustment, I would spin my work piece a small amount and then recheck both pins. I did this several times until my indicator read zero on both pins and then tightened the nut. This was a slow process but it worked for me.
 

Here are the X and Y coordinates that I used for each dowel pin hole. To find each X and Y position, I drew all the holes in my CAD system, analyzed each hole and then put those numbers in Excel to print out.
 

Here is the platform cutouts all finished. I have a little more machining to do here but I'll come back later for that. Now it's time to work on the top called the lantern room, where the windows will be.
 

A few minutes later I had most of the lathe stuff finished, including a 1/2" hole through the center. If you look close you can see I'm using my part-off tool to cut off my work piece. I have more work to do on this piece but I'll return it later.
 

I'm going to use two dowel pins to locate the lantern room, the platform and the base together. After looking at some of the dowel rod that I had, it was undersize and out of round. So I made my own 3/8" diameter wooden dowel pins out of alder.