If confronted by that scenario, I might glue the wing tops to the fuselage, keeping the lower one separate. If filler was required on the lower half, you may try sheet or strip styrene, glued to the wing or fuselage. This would allow you to reassemble without damaging the paint. If the bird is wearing camo, the demarcation woulf fall along the leading edge seam. Interesting question. There are probably many approaches out there, this is the only one I can think of.
Good luck, I hope it turns out well !