When you say "turn around", do you mean simply plug it in on the other side in upright position or flip the unit over and plug it in?
note: I took a look at the A500 MB and if you are looking directly at the slot, contact 1 is on the far left. Are you saying that contact 1 on the Amiga 1000 is also on the far left, or is it on the far right? If it is also on the far left, I would be able to plug it in upright but the front of the expansion would be faced toward the back of the computer.