So you throw the thick end of £100k or so at OAA (or CTC or FTE or Cabair or whoever?) and they can't even include a SEP(L) class rating
I suspect you'll have the minimum experience requirements in a SEP(L) from your CPL course, do you?
Was the flying done in the UK? Not an insurmountable obstacle if not.
So really, it's just some revision if you think it's needed, LST and application & fee to the CAA.