ORIGINAL: FLYBOY
Ballence it level, right on the spar, and you can stick it right to the covering, but I would put a small screw through it into some hard wood at the tail.
Note the wording - a
small screw. I've seen some guys use a screw that's too large (coz its all they have handy), and the result is that the small strip of lead now has a pretty large hole in it - that makes a weak point which can cause the lead to break and fall off.
Gordon