Sleeved tubing construction for Barrychuck's Thing O Matic Z stage mod

This is a derivative or alternate construction method of the Thing O Matic Z stage mod by barrychuck http://www.thingiverse.com/thing:6184 . [If you can tell me how to do a linked derivative I will make it so]

The hole enlargement for the 21/32" tubing can be problematic to do accurately. I found a way to do it in my shop using more commonly available drill sizes and tools. Accurately.

Basically, if the pieces of 21/32" tubing are sleeved, with 21/32" tubing then they fit perfectly inside