Hey aerografixs,
That's a pretty interesting tab setup. A while back I did an 80" Cap for a guy with 2 Jr 4131 (90 oz ea) on the rudder. He claimed it was marginal at best. I would say the claim vs. skill might be questioned. Actually it was more pain than anything as it was constantly buzzing and very difficult to keep both servos from fighting each other. Not to mention radio programming.
If you are only using a 40 oz servo plus boost tab....that's great. Just saved about $75 in servo cost + 3/4 the cost of the second and ??? $$$$ in labor and pain setting up. From the picture it looks pretty tough too. Nice job. The neat thing is that you always have "power" assist like power steering as long as there is air flow over the surface. more or less proportional....more air flow more power assist. Even with no air flow the 40 oz can move the surface easily. Utopia!!!
As I was saying earlier, on larger planes it is much more effective than smaller planes. Likewise on larger surfaces it is more effective. Also the farther away from the hinge line the better too..as is your system.
Let me know how it performs.
By the way I checked out your web site listed. You got some very interesting stuuf there I like the fiber optic cables. As J.O. noted these have been in industry for years. I use them all the time just like wire in our machine control sensors. I'm about ready to start another large war bird so I'll be interested in using some of these. RC has needed this for a long time.

more later
bentwings