Limited time and resources prompted a new design for this baby.  The old design required a bit more setup on my primitive mill so I had to simplify it a bit. 

Here is the original design.  More can be read about it here.  Seatmast Topper Ver. 1
Seatmast Ver 1
The main problem was the main body of the assembly.  The extrusions on the top required extra setup to get to.  Also, the yokes were a nice design and are very well optimized in geometry but again took more time than necessary.  The whole Assembly weighs a scant 61 grams! 
 
Seatmast Ver 2 Assembly
Seatmast Ver 2 Exploded
The new design adds a component piece but saves a bunch of time and simplifies the manufacturing process quite a bit.  The seatmast body should take about 3 setups to machine and will take about half the time.  The Yokes have also been simplified.  I don’t particularly like the new simple design due to its lack of sophistication but a lathe will turn that out in no time as opposed to the shapely first design.  A simple center bridge is added to the assembly.  Overall the new assembly is 72 grams, growing 11grams over the more optimized design but should take about half the time to make.