Your Gouldians are in excellent condition - Great to see. What you have however is much rarer - as a Judge of finches at many Shows, I can tell you the reddish pinstrip between the purple breast & the yellow belly is a fabulous attribute. Line breed these please - they are rare in modern 'Gouldian' aviculture, & definetly keep him away from the mutations.
Thanks :). You'll be horrified to know that I have paid almost no attention to the red band until this year! Then I found a Gouldian in a grubby suburban pet store that had the most amazing red-orange band I've ever seen, like a fiery sunset. He's turned out to be a fab breeder, so I will cross his kids with my existing lines. (I prefer not to line breed, or barely, because the genetic disadvantage this creates is not worth it IMHO.)