Very cool bike. My '81 UO9 has either Chrolux or Rigda 27" steel wheels, I just can't recall exactly and am not there to check. I may be misspelling the brand as well, but the more I think about it Chrolux seems to stand out, but definitely steel wheels. Having one steel and one alloy means there obvioulsy has been some changes. Your boy looks like he is having a blast!