You are not missing much by not having the construction manual or plans. The Model Tech construction manual is a generic one that has pictures for a high wing trainer. The plans are on five sheets of typewriter size paper at about 1/3 scale. From the plans, I calculated the CG for the plane should be about 135mm from the leading edge. On my Saphir II I have the CG a little ahead of 145 mm. At that setting, the elevator position for level flight changes slightly from upright to inverted. The rolls and stall turns are good. Spins are OK and snaps are poor. A more rearward CG may help the snaps but my plane is heavy and the Saphir II does have a long wingspan. Moving the CG back might not be that beneficial. If you wish, I could scan the plans and send them to you.

Allan