We've got a dormer window with lead cheeks and the lead isn't particularly
well fixed where the sides meet the front, as you can see:

http://oi53.tinypic.com/2vryae1.jpg

The wind frequently hits the dormer head on (we live in a windy location)
and makes the lead sheet flap about a bit. I want to fix it properly before
it gets ripped/damaged during the autumn high winds.

My idea was simply to use some clear silicone inbetween the lead to make a
seal, but I'm wondering if there is a proper or better way for fixing. I
think the dormer frame is all wood, so maybe there are proper nails or
fixings available I can use.

Any ideas?

Thanks