I don't know about an easy retro-fit for you, but if I was designing this from scratch, I'd think about using the press arms as parts of a manifold (not dissimilar to a motorcycle using its frame as an oil sump.) Of course, a similar affect would probably be more easily done with lines running through the arms.
If your vacuum pump could be mounted close to the center of the carousel, it could spin and the lines could be fixed.