My oven is a GE Profile Spacemaker model JVM1490SD003 made in 2003. I've ordered both the inline fuse and upper heat thermostat online and since the oven must be removed anyway, I'll replace those parts and check for any other "crispy critters" inside.
If the oven must be replaced, I'd prefer a newer version of the same unit so I can use the same mounting bracket, vent duct location etc.
I'm fortunate to have an engineering background and a brother (where we're parked) that was formerly head of Litton Engineering, Microwave oven division.
Thanks for all the good advice and suggestions.