The original brackets are not an orderable item within Cisco. Usually most vendors will have 3rd party brackets, ranging in different sizes.
If you do a search for "Cisco Small Business 300 Series 19" (1RU) Rack Mount Kit"
The screw holes on the mount Kit will match up with any standard size 19" Small Business Switch. 500, 300, or 200.
When you get to the smaller form factors, like SG300-08, 10 you will have a different look to the screw holes.
See attached picture for examples.
Under certain conditions, Cisco can provide a replacement set.
It would be worth it to call in and open a case with one of the engineers and try that first. Call 1-866-606-1866 to open a case.
Another option if it is more convenient for you is to start a chat. Here is the link to do that.
https://supportforums.cisco.com/community/4841/online-chat-support
Hope this helps everyone.
Eric Moyers
