The G1 toy had it flip into his chest and come out of his back, leaving it stuck behind his head. Sure that predates the cartoon, but the Robot Masters Starscream kind of does the same thing.
And with the Henkei SS, you open his chest, rotate the nose/cockpit 180, place it in his chest and close it back. Leaving Starscream with a piece of "kibble" behind his head again.
And for the MP-11 there's that awkward back hood that attempts to hide his nosecone.
But, what if you pushed the nose inside (spring), flipped the cockpit to his chest like in the cartoon, and his head popped out like the G1 Hotspot toy? I'm not a toy-maker but I think that could work. (and be super fun to transform back and forth.)
Here's a rough sketch for fun:

I have ideas how to handle the rest of the toy, mostly taking notes from the Henkei version.