Mintflavour,
In that case you are correct it is a grey area. As doing the IR exams seperatley do allow you to have an IR but not an ATPL. What you would need (although does not exist) would be some sort of ATPL 'upgrade' exams to go from just the CPL exams to an ATPL without having to do all 14 exams. There should be no problem working for an airline as an FO with just a CPL/IR though.