Hugh, welcome to the NAWCC Message Board. Thanks for posting the photo of your clock. We have a "Clock Parts Wanted" thread HERE, if you would post a request there that you are looking for a replacement bezel it could be possible that another member could have one available. All actual transactions need to be off-line by email or Private Message.
If you could post a photo of the back of your movement showing the complete back as well as a closeup of the logos and serial number, we should be able to provide you with a model number and the year your clock was made. Will look forward to seeing the photos.
John - your chart posted allowed me to guess at date of manufacturing - early 1922 ?
Serial number: 2418997. Freiburg logo on the left, Medaille logo on the right... here are the pics (can do fullsize if needed)