KIWIIANO Appears to work, but I ran into fish-hooks. My MacBook's TM ext drive initially refused to mount when plugged into a G4 iBook running Tiger. When it did mount and I successfully instructed the MacBook to access it via Airport and ethernet, TM started to recreate the backups from scratch then ran out of room. It's a nominally 160GB drive to back up a 120GB internal with about 84GB used. The 160 already had TM files on board but when mounted as a networked volume those files were ignored. I suspect that the network drive required for TM is better attached to a Leopardised Mac. The drive mounting process seems a bit random and may cause the network connection to hang.
(Version 1.0)