Yo, awesome gravel (and some tucked-away sealed twisties) playground anywhere between Seymour in the West / Midland Hwy in the East....Goulburn Vly Hwy in the Sth and Hume in the North.
Slow part of Ponkeen Ck Rd. is Ponkeen Creek bridge and up through the farm buildings until the cattle grid/ gate on the downhill....then it's all quick to the last dip at Hughes Creek bridge.
As for the Brown....it's that time of year again (breeding season) and they're out and about anywhere there's water and bare patches for sunning (asphalt/ clay etc)
Try Red Gate Ln and Wickett Hill, Killeens Hill etc....Sinclairs Ln could be a bit rough after the rains (ends are clean as they lead to farms, mid-section can be pretty rough).
Mt. Wombat, the eastern half from Ruffy will make it a complete east-west crossing from Swanpool to Seymour incl. a WW2 plane-crash memorial in the bush....it's easy to spend 2-3 solid days up there scooting the gravel and granite-boulders. Tarcombe Rd./ Upton Rd. scenic rollercoaster, Lambing Gully, Roxeys Lane, Mt. Bernard, McLeans, Welby Track and endless other stuff...and that's only the north-west of that "square".
All within a few k's of the main roads and towns and yet entirely deserted, even on the weekends.