The secret was to trim as much waste off the decal as possible. It is easier to get a curve in a thin decal than a fat one. Next, I consider it legitimate to cut large decals in two or even three pieces. Especially where the body curves change direction. All three pieces are applied to the model and jockeyed into position before tamping the extra moisture from them. With shorter decals I might even cut into the decal where the curves are to allow the decal to flex a bit more, but be warned. Handling the decals too much after they have been applied will see them disintegrate.
There must be approacing fifty separate decals on this model!!
I would normally give the decals a coat of clear acrylic before applying them, but because of the difficulties, I bought a can of proprietry decal bonder and coated the sheet lightly before cutting. All the coating processes were allowed to dry for a day before handling.