Way back in SDL #79 I commented on a change in Ron's art. In earlier works he would use shade to suggest outlines rather than draw hard lines round his characters, but that seems to change and progress to this very clean style with outlines on all the figures and less black overall. Whether it's a separate inker or an editorial decision I don't know, it's still Ron but not the Ron I used to know! Mind you some of the scripts don't give him the opportunity to use his imagination to the full...
Link to the book:
Super Detective Library 133 - The Mystery of the Frozen World