Unfortunately, no amount of polishing is ever going to restore the reflector to the level of reflection it had when it had its coating. Sadly, with that reflector the light is probably always going to be a flooder.
Your options:
1. You could try polishing the current reflector. You might be able to convert it from a pure flooder to just a mostly flooder. It won't be a thrower though.
2. You could try installing an aspheric lens in place of the stock lens.
3. Perhaps you could order a replacement reflector.
4. you could locate a plating shop and hire them to recoat the reflector (this will probably cost far more than you paid for the light).
IMPORTANT NOTE:
NEVER directly touch a coated flashlight reflector with anything with the sole exception of air (compressed air is ok). Pouring over the reflector or soaking it in Liquids like alcohol or distilled water might also be ok, but might leave spots. NEVER EVER touch the reflector with anything else. No fingers, no cloth, no brushes... nothing. The coating is extremely delicate. Even just lightly brushing it with a finger might be enough to permanently damage it.
what I did to the reflector
and what the beam looks like up close
what the beam looks like across the road
