Hi onnets & treasure-hearts,
Thanks for alerting us to this problem. We have confirmed that the Custom Item Specifics link is no longer showing up for at least some eBay AU categories and our technical team is currently working to resolve the problem as soon as possible, although I am uncertain when we will be able to get a solution in place at the moment.
I will keep you posted through this thread as any additional information on this topic becomes available. We apologize for the inconvenience this issue is causing.
-Mike