I am not a super expert in fish medicine so don't feel oblinged to accept any answers. I just notice that your questions has gone unanswered for so long that I would like to try and help. I saw it unanswered late last night and decided to polish up on my fish medicine.
Do you know what the ingredients were in the Ich medicine? How long did you use it for? Did you use it as a dip or bath?
I assume you have addressed your water quality concerns? pH, alkalinity, chlorine, temp, hardness, salinity, ozone ammonia and dissolved oxygen.
How long have you had this guy? Any new fish in the tank or is he alone?
Any other lesions on his body? You mention that his gills are red, is this more than usual? And do you notice any reddend areas elsewhere on his body?
Yes swim bladder disease is also what I thought best fit his symptoms. The most common causes were parasites and bacterial infection. I noticed that you tried penicillin. Your treatment with formalin and malachite green is one of the best recommendations for parasites.
I would recommend trying a copper sulfate solution (also from pet shop) as this is a good general parasite and bacteriacidal treatment. Tetracycline antibiotics are used commonly in fish, but so much so that some bacteria are becoming resistant. But I would also try this as well. Also easily obtained at most pet shops.
Copper sulfate treatment is 0.15 to .2ppm (parts per million). You can gradually increase the concentration 0.01ppm per day up to .2ppm in sensitive fish. Also check the alkalinity of your water. A higher concentration of copper sulfate is needed as the alkalinity of the water rises. You want your alkalinity to be between 50mg/liter and 250mg/liter.
If I can help in any other way please let me know. Good luck to you and it is nice to see people devoted to pets that many people seem to think of as disposable.