It's going to take a good 3-4 years to add some quality width and depth to that back, but once you've got that, you'll have a legitimate pro physique. Just take your time and you'll be just fine. 
I am not sure Peter would ever get the kind of back that could compare standing next to a Cutler, Coleman or Dexter, etc.
However, I am certain the man can and will earn a pro card. It is due to classic physiques like Peter's and guys like David Henry that I firmly support wt classes in the pros. I think Peter has a very marketable look and should do well in terms of endorsement /supplement deals. However, based on the current pro standards it would be tough for him to be a top 10 Olympia level pro.
Howard