That's a pretty nice concept you have there. Hmm, you might want to use different elements and gimmicks that are fitting to the factory theme but haven't been used in one of world 8's stages.
Let me give you a few suggestions. Maybe you like some of them:
1.) What about using some sort of ventilators? They might be used in different ways. They might either push you from platforms or they might even aspirate you. You might compare those to the enemies in Airman's stage from MM 1. The ventilators might also be on the ground and when you jump on them they psuh you upwards and thus grant you the ability to hover in air.
2.) What about the cloud that has been used in SMWCP's Zephyr Manor. They could fit in here nicely. You could have to dodge electricity, canons, spikes or whatever you want to use there.
3.) You might also use an airplane instead of said cloud, thus including an airpop segment. After all, we don't have any of these in world 6 yet and it might be a good addition.
4.) Another part might include a jetpack segment. I don't speak of the jetpacks that we have seen in Airotastic Assault. I speak of the jetpacks being used in Kipernal's Musical Madness (room 3). Since it is only used in this small room you might also include one segment in this stage.
Now these are some ideas I had and maybe you like my suggestions.
As I said before I think that you could actually build a great stage. All it needs is one awesome gimmick that has not been seen in another world 6 stage or even several gimmicks if you have the motivation to do some extra work on your stage.
I am also looking forward to escaping the factory when it crashes (some scrolling in the background might create this affect). You might want to use YCZ's code for crashing objects. In this case they would need to be redrawn to objects that belong in a factory, like pipes, vents etc.