That exact model number is not showing up, so you may want to check the tag on or in the unit and look here
Most of the models in this class of ovens were not really made to be serviced, so GE only makes the turntable parts available.
It also sounds like your bulb is an assembly - the socket and bulb and one piece.
So your local appliance parts store should have a generic replacement for it. You should take the bulb.
Be careful when disconnecting the leads.