"What is a Fender “FSR” instrument or amplifier and why can't I find information on them?"
“FSR” stands for Fender Special Run. These products are specially commissioned by individual dealers and built to their specifications. As they aren't regular production models, FSR instruments and amps aren't generally available to every dealer, and Fender seldom provide specs or listings for them on its website. Your local dealer, however, should be able to provide detailed specs for any FSR products they offer."
Which, I'm sorry to say, tells you nothing. Like that classic line about the Saturday Evening Post, apparently "FSR" means whatever they point at when they say it.