Not really sure what you last post is about.
The reason you can't use the Migration Assistant system in your new Mac is because your old Mac is a PowerPC based system. It is not because you are running Leopard. I looked at the Apple Kowledge base article on using Migration Assistant and it has no references to what older OS X versions it can or can't be used with. Leopard OS X is only 4 years old, last Point update for it was in August of 2009 and shortly after that Snow Leopard came out.
So I would think the Mavericks Migration assistant system would work with Leopard if it was installed on a Intel CPU based Mac computer but not from a PowerPC CPU based computer. Like I said your old computer is at least 8 years old.
All the best to you getting your files over to your new Mac computer.
margofromnld wrote:
I have always updated the OS. As far as I know there is no update from 10.5.8 available for a G4. In my log I can see updates until Sept. 2013 for 10.5.8. Maybe I don't understand what you mean?