Yep, Thats fowl Pox(Dry Form)..Iodine, Black Shoe polish or the big felt tipped Magic markers will help dry the sores, but will do nothing for the virus, it runs it's course in individual birds in about two weeks, But can take months to go through the whole flock Vitamin therapy is helpful..things go fairly smoothly unless complicated by the wet form(inside mouth and throat) in this case it's hard to control, as scrapping the sores only spreads it,,Separating infected birds from the non infected does no good unless you have mosquito proof inclosures to put them in..Vaccination will stop further outbreaks in healthy birds.......You may want to think about vaccinating in the future