RE: Super Sporster BIPE
This model did not have interplane (outer) struts in stock form and I haven't heard the need for them. Perhaps the original owner experimented with them at some time for aesthetic reasons?
If you just want to play with the CG. You could always stick a piece of lead in the nose under the engine instead of going through the trouble of moving the engine. This would at least let you see how the model behaves in the air before you carve up the nose.
The easiest way to check the wing incidence is to use a tool like the Robart incidence meter or anything else similar. Without one of these, you can always use a ruler to measure the leading (center) and trailing edge to your work bench with the fuse blocked up level to your bench. If the model behaves normally in flight other than not slowing down on landing, I would not mess with moving the wings.
John