I would say he's a mix but there is no question there is some Sussex in him. Would explain the characteristics, and differences between opinions here. But I do agree with 'donrae' that if there were any rare breeds that could have contributed to the genetics the seller would definitely have mentioned it and prices would significantly increase. So I doubt that there are any Swedish or Icelandic in there, but again you never know. What did you pay for him, if you don't mind me asking?