Modifying Ajax into Sydney will also require rebuilding the stern deck area including the superstructure. I have an article with drawings somewhere, let me dig it up and I'll upload it to my freewebs account and post a link. It's available elsewhere online (I unfortunately lost the link) so no problems. With proper funnels and aircraft, rebuilding the aft deck is no problem, its all geometric shapes and just one deck…
…Here's the link to the article. It's a pdf file and covers the Leander and Arethusa class ships. It's pretty good on accuracy, and with some PE and, of course, Matty's conversion set, and we have an excellent Sydney. Hope this info helps everyone.