The first real step was to take the M5 apart and see what kind of tolerances I would be working with and how everything was going to fit together. I ended up adding a couple flat washers to make up for the space differences between the allen wrenches I removed and the keys I added.



I was pleased to find that your standard house and car keys are the perfect length to fit snugly inside the folded M5, so you don't have to worry about adjusting the position of the keyholes. The only part of my keys that really required any modification at all were the little square holes. I imagine there are key blanks out there that have a large enough hole to work right out of the box with no modification at all, but alas, I would had to make my square keys fit a round peg.