I'm presuming that this is a Simpson Nova 65-867
By the look of all the data I can find, this is an Australian appliance. I'm in the UK, and I was presuming that you were in the US, but maybe you're in OZ.
If you are then you can go to http://www.alliedappliance.com.au/about_allied_appliance.htm
And mail them with a request for help. They advertise loads of spare parts for your oven (but not glass in the listings I have seen). I imagine that they will be able to source what you need.
You can also make enquiries at The Big Warehouse.com, who also stock parts for your oven:https://spares.bigwarehouse.com.au/contact_us.php?osCsid=3b1cdec4545fb97a677f2646a2b69530
Finally, go directly to Simpson. Contact information as follows:
Simpson appliances are stocked by a wide selection of quality electrical retailers throughout Australia.
To find your nearest outlet, please call our dedicated customer care number:
1300 363 640
For service related questions please call:
13 13 49
For information about spare parts call:
13 13 50 http://www.simpson.com.au/locator/search/retailer/
Worth noting that Simpson are part of the Electrolux group, so you may get help through a local Electrolux agent as well.