One group solved the tank; another solved the location.
Upper Blessington Rd near Foleys Rd (Blessington, Tas.): Ex-TGR ASG front tank at a sawmill. Sat.31.8.85. (Roderick Smith)
Modifications show that it was TGR, not EBR.
That is also consistent with the location.
We had come from Evandale to Ben Lomond to ski, but the the weather was vile and we abandoned the plan.
With a day to fill, we decided on as east-coast circuit.
Hence, at the T junction we turned right for Blessington, Upper Blessington, Upper Esk and Mathinna to Fingal, then to St Marys, St Helens, Legerwood, Scottsdale and on to Devonport for the night for Don River Railway next day.
The tank would have been a surprise, but quite obvious from the road.
I am not finding the sawmill on Google Earth today; it may well have vanished over 30 years.