With some fiddling around I managed to separate the Optimus bits from Orion's back, and then reattach them to Optimus. This means you can display Optimus and Orion at the same time. I was glad to find out Orion could be taken apart without popping pins, and that this is totally reversible with just three screws. I keep the screws stored in the original holes so they won't get misplaced. The chest can still open to view the Matrix. I had a simple Lego panel filling in Optimus' back, but revisited to hide the 'Lego bumps'. Perhaps I should build a jet pack onto there. The bare minimum of what you need however, is only the head connector below (which connects via the blue Lego pieces into the back of the Matrix core), but there is some 'light leakage' quite noticeable from the front of each after removing their back kibble, so it looks better from the front if there's something back there. *note: the C-clip Lego pieces must be the type where the 'C' doesn't go right to the edge of the square, or they will not fit on Optimus' neck piece. Here are the pieces I used to fill in Orion's back, but you can use any pieces you like really. Just build them onto the 3x2 brick: And for Optimus, you need the head connector, which I built one part of the back onto: And the second part uses a 3x2 brick that fits over the screw peg, and simply friction fits up onto the other back piece. Pleased with how the Lego pieces are just the perfect sizes to connect snugly to both. If any questions, or anything unclear feel free to ask away, as well as give suggestions, offer other ideas, or leave any sort of comments.