OK, I removed the flywheel and it's a single key Stihl 1122 400 1201a. Is the module in the picture a 3-leg coil?. Is that the only one that will work?
As long as you have the 1201 flywheel you can use just about coil that will bolt in there. It looks like to me your case has the mounts for the regular 0000 400 1300 coil and those all over ebay.
Here's an example: http://www.ebay.com/itm/STIHL-IGNIT...294?pt=LH_DefaultDomain_0&hash=item5d45d358ee