Travelling around the Adelaide Hills, I spotted this oldie but a goodie. Typical of many that dot the landscape around here.

Who lived here?
How long ago did they vacate the building?
Why did they leave?
Looks like it was a great location for a renovation into a B&B?
So many questions so few answers, so if anyone can fill us in on some history it would be greatly appreciated.
At the listed co-rdinates is a sign, with four numbers upon it. = ABCD
E = A+B
F = A+D
G = B-A
The cache can be found at...
S34 5B.DGA E138 5F.C0E
Checksums... S=12 E=16
The seemingly abandoned house is on private property, but the cache is accessible without going over any fences or a gate, so please do not enter without express permission of the land owner.
Also be careful at GZ, and watch out for traffic, please pull well off the road at listed and GZ. DON'T PARK ACROSS DRIVEWAYS