Shifter (&brake) Linkage

Since the start of this project, nothing has puzzled me more than how I was going to set up the brake and shift levers. 
I have spent hours in research and more hours in thought over the best method for achieving efficient shifts, drawing diagrams and mashing various possibilities together.  On a few forums there appeared to be little worry over the shifter side when replacing stock pegs with rearsets, but concern on how to set up the brake.  I felt the opposite problem, since the brake side has a spline shaft to which a shorter lever could be fit, or some other linkage arm attached.   There are no rearsets which accommodate the rear drum setup on the 850T; they all seem to pick up from later models (while almost identical have differences), leaving me with the task to engineer a linkage.  Part of the problem is in the frame plates designed to support both the brake rod as well as the shifter rod.  As I had to keep the brake rod (drum rear) I could not simply toss these frame plates, or come up with a way to also keep the shift rod (it is attached to the shift pedal).
I decided on the Tarozzi brand rearsets and picked up a set of pegs and shift levers from Fast From The Past (as shown below).  Jim substituted one linkage arm for the idea I had in mind.

Tarozzi brand rearsets and levers

For the shift side, I finally settled on running a spline shaft through the frame plate/bracket and connecting it to an arm to activate the transmission input shaft (but not without going back and forth dozens of times as to whether this was really the best path).  Part of my concern was in introducing any slop in the linkages, especially side to side or up/down movement when transferring a down foot movement into a forward linkage movement, then into a downward transmission shaft movement.  
First called for buying a drill large enough to accommodate the size of the spline shaft provided with the rearsets.  Unfortunately (which I still find hard to believe) 16mm is the smallest spline shaft size they make.  This meant finding a 5/8" drill bit to go through steel (grumble, grumble, $25 later - all in all I spent $100 more in tools and linkage parts in addition to the $300 original cost of the rearsets).

Taking the leap with any irreversible step is the hardest part; once started, you are committed and it gets easier to keep going.  I leveled and secured the plate for drilling the 16mm (5/8") hole.  It took a while but after roughly 30 min of drilling the hole was made.  I stopped just short of the end since I could see that the 16mm hole left very little steel remaining on either side of the cupped section (which was for the stock shifter rod).  I figured I was going to have cut off some of this cap anyway, to ensure the length of the spline shaft aligned with the transmission linkage.
So cap end cut off; and notice in the photo below the arm that had to be shortened as well (cut above where new hole marked with Sharpie).  Just a new hole still to drill in this to accept a linkage rod end.  And cutting of bushing for tight 16mm fit.

The final linkage set up (without rod ends yet) is below, along with an 'exploded' view.  I bought a bushing that I modified to fit snugly over the spline shaft, as well as butt against the bracket and the linkage arm to minimize sideways or up/down movement.  All fits very snug; as long as the leverage provided by the shortened arm is ok, will hopefully work great!  At this point, a few rod ends are on order to complete both brake and shift sides before they can be mounted on the bike, adjusted and tested.