I'll see if I can get dip strips tonight from Petco.
As far as companies, the tetracycline was API Aquarium Pharmaceuticals brand and I'm fairly convinced it's what did the trick for the fin rot. Even my friends (I live in a dorm) comment on how much better he looks.
The filter is a Whisper 3i and I've since raised it out of the water and being that it's bubble powered this slowed the flow considerably.
Regarding the torn-out scale, I don't think it looks indented but raised (I got a couple second opinions on this one that agree)
I don't think it looks particularly furry, more like a MUCH less severe version of this: http://www.ultimatebettas.com/index.php?showtopic=17853
(I've been looking all over for a diagnosis)
I have no idea how old he is, just got him two weeks ago.
When I brought him home he had pretty severe fin rot. I posted about it here if you need a detailed description: http://www.bettafish.com/showthread.php?t=62069
I had been conditioning with Nutrafin but during the treatment I switched conditioners to Reef Safe Microbe-Lift/Aquatic Stress Relief. It's supposed to remove the chlorine and chloramine, heavy metals, and be soothing for the fish. I grabbed it because it was bundled with two other bottles that I used to jumpstart the tanks cycling after I did a 100% water change following the first tetracycline treatment.
I added 1.5 teaspoons to the tank of aquarium salt because the box said add 1 tablespoon for every 5 gallons for enhanced disease treatment. That was on Sunday night, and that was the first time I had ever added salt.