I think after this amount of time, they have moved on, so maybe it is time to resort to tracking down the last 1-3 issues from ebay.uk...

Either check the main listings for new additions,

Or, check out these two listings that have entire collections listed as individual volumes, and select the ones you need.

This one has 2 copies of 77 Disolution left, (expensive) and a lot of the later volumes.

This one has some different volumes as well (cheaper).

Both of them will post to Australia (about the same amount), but factor in shipping too.