If you have the broken piece, hold it up in place, then run a piece of thread or fishing line thru the slot in the slat, around both sides of the clip, and tie the front and back half together. Another loop above the slat will help..The valance will hide it.
That was my next suggestion to mcgyver it lol. He doesn't even need the other piece to do that I'd drill a hole through the remaining piece after I crazy glued the vane to the remaining one and run a wire through itIf you have the broken piece, hold it up in place, then run a piece of thread or fishing line thru the slot in the slat, around both sides of the clip, and tie the front and back half together. Another loop above the slat will help..The valance will hide it.
That was my next suggestion to mcgyver it lol.
Ok special tool needed?
View attachment 1201138
This "key" is a position stop. When inserting the new one, you'll want to ascertain the correct positioning. The old one should snap out from left to right, then down. Reverse for the new one.