A stock 92-95 Mustang starter will look very similar to this. A 91-prior starter will be a bit bigger in diameter, won't have the solenoid on it, & will only have one large wire running to it.
For further diagnosis, I'm sure some of the wiring diagrams done by tmoss can be of help. Mustang FAQ - Engine Information
For further diagnosis, I'm sure some of the wiring diagrams done by tmoss can be of help. Mustang FAQ - Engine Information