Since you got no brake lights & also your shifter is locked... I bet you have a broken or disconnected brake pedal switch. That's what turns on the brake lights & also signals the shift-lock solenoid to release the lever.

Look up at the hinge of the brake pedal. There should be a switch somewhere up there, maybe it acts as the stop for the pedal when you aren't pressing the brakes. (Probably depends on what year, I don't own a '91.) Broken switch? Unplugged? Simply came out of it's bracket? Look for stuff like that before you buy a new shift lock solenoid..