Keep in mind that if the illusion is going to appear to interact with a real physical object (the factory machines) you'll have to control your sight lines carefully. If the machine moves in relation to the ghost (or vice versa) as your guests walk by it will become obvious that the ghost is a projection & the illusion will be spoiled. Your best bet would be to have the scene only visible from a small area as your guests walk by. Having the ghost's torso & arms constantly moving can help mask the difference in viewing angle, too. I can't wait to see video of this - I love Pepper's ghosts.