I don't know if this works in your scale, but in 1/48 this is what I do:
I use pe control horns, mostly from Eduard. When I remove them from the fret, I leave as much from the attatchment as possjble on there. What i mean is that I give the horn a small pin so to say.
That way I can drill a hole (very small, you only need to place the pin) where the horn will come and give it an extra strong bond. Sometimes (with the tails almost always) I need to drill all the way through and place both sides in the same hole, but if you are very carefull with glue, the hole stays open to insert the oposite side
never had any trouble with a contol horn letting go.