It says Oxo on busses and Sportster on detuned FatboyUltraglides but.....
Just a silly name to differentiate it from the other versions, but who cares, 29 HP is enough to have fun so long as you stay off the motorways. If you want to break the traffic laws and play with the boom-box kids at traffic lights, get a KTM it'll win every time. I know the old men in over tight leathers will claim anything under a litre that doesn't have your bum higher than your brain is a girls bike, but I honestly don't thing these people ride anymore, 80 mph is it, traffic or cameras make anything else pointless so you may as well have that as the 100% point in the bikes performance and use what you bought.
As for tuning it to be a Goldstar, I wouldn't bother you'll just make it as unreliable as a Goldstar and you'll be the only one who'll really know what you did to it. None of the rocker and piston and exhaust people seem to push the unglamorous, hard to fit bits like 50HP bearings that make the thing usable at higher power. If it was that easy the factory would do it.
I'm still hoping Yamaha bring the SR400 (30 HP) in before I'm due a bike, but these Enfields are certainly on the list of bikes I'll go look at. The owners sites are full of Lucas-esque tales of electrical woes mind. I was lucky with my Enfield it was one of the good ones but it would worry me.
Andy