It's likely a GT. The lower trim should be silver unless the whole car has been repainted, and the quarterwindows should designate GT unless they are missing or have been replaced. Underneath the bra, the nose badge should also say Fiero GT.
Regarding the dash, there's a dash up here in the u pull it. An 85GT that has no cracks on the corners. Those vents are commonly referred to as "knee-knockers". You'll soon find out why they're called that and why the corners are cracked. Usually the drivers side goes first.
By your description of the exhaust leaks, the leaks are between the manifold and the engine head? As TopNotch suggested, the V6 had a problem with the exhaust manifold itself developing a crack around the # 6 port. This is the port closest to the driver's back.
The Fiero didn't come with heat wrap around the exhaust system. If you have it, it was added by a previous owner. Might be best to remove it if it's rotted and hanging loose.