If I’m not mistaken, Seven News Melbourne is produced in SD. Any HD channel airings (pre-2010, that one off for Grand Final Day 2015, May 2016-now) of the bulletin would be upconverted.
AFAIK, Sydney (live studio camera footage + graphics only) and Perth are the only markets that have any level of HD production from Seven News. Hopefully this will change in 2018, but I’m not holding my breath for that…