ORIGINAL: anonymouse
If all you need is the centre of gravity or the balance point, you don't need the instructions. Normally the CG is about 1/3 the chord. Measure back from the leading edge at the side of the fuselage and use that for a starting point. It will fly, but you may want to fine tune it in to your preferences...
This is assuming the wing is a constant chord.....
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Anonymous is dead on target.
Just measure back to the 1/3rd point of the leading edge, balance it there and you are good to go. This applies to any symmetrical or semi-symmetrical airfoil equipped, constant chord wing.
To be conservative (safe), don't include the ailerons in the calculation if they are strip ailerons. If barn door (not this model), ignore them since they are an integral part of the wing.
It needs to be said that just like "factory needle valve settings", this is a safe starting point. Not the final/finest position. However, if you are happy with how the model flies with this CG position - just leave it like it is.
Ed Cregger