It looks like Fowl Pox to me. I'm not sure how much information you've found out about Fowl Pox, so here is some information:
Fowl pox is a viral disease. It is spread by flying insects like mosquitoes. There's no treatment for the disease itself, but to make it spread slower, treat your area for mosquitoes and flies. Also, isolate the infected birds. Birds recover from Fowl Pox in about three weeks, usually. The mortality is generally low.
To make the bird more comfortable, you can put petroleum jelly mixed with sulphur on the scabs. This will soften the scabs. Putting some iodine on the scabs, too, will help the bird heal. Your bird appears to have dry fowl pox for now, but it may progress to wet fowl pox, which can invade the throat, causing breathing/eating difficulties. You may have to tube feed if this occurs.
Though the disease is viral, a secondary bacterial infection could form due to the stress that the bird is experiencing. Because of this, you might want to get some antibiotics. Terramycin or Tetroxy HCA-280 are two good antibiotics.