Well... crap. Yotsuya was kind enough to dig out the coin door for me, but the spacing turned out to be too small for my modified mech. I would have had to modify it anyway. After much deliberation, I decided to keep it as is and just set out about modifying the 2 coin door I had. Here's a brief walkthrough:
If the existing slots had been mounted just another 1/8 inch apart I could have just squeezed the third in-between. For some reason, the designers decided to make my life a little harder. So, I had to cut a new opening in the middle for the new slot and also slide one of the existing ones over a little bit.
First, I traced a template of the cut-outs onto graph paper:
Then I cut out the template with an exacto knife:
Then I took a paint pen and colored in the cut outs:
Drilled out the corners:
I guess I forgot to take pics, but next I basically just ground out all the yellow parts. The whole proess took about 2 hours from start to finish.
Still need to loosen them up a little and re-center but here's how it came out. Not perfect, but I'm pretty pleased.
Thanks to Yotsuya again for working with me to get the door. I'm hoping to use it for something someday. Maybe a future build once I get a smaller RFID reader.