Rod222, thank you for all of that information, it will be interesting to see what else can be researched and pieced together about this area.
Bobby De La Rue, I noted the problem of closure before issue of the 2d stamp in my first post:
Quote:
The diamond jubilee stamp that bears the numeral cancellation was issued in 1897, unfortunately 10 years after 'Ballast Siding' apparently closed.
With respect to the closure date, it looks like it should be 1883 as per Hopson and Tobin, i.e.
14 years before the issue of the 2d Diamond Jubilee (Record Reign) stamp.
As Bobby De La Rue mentioned, Monkey and Ballast Siding were swapped between the first and second editions of Freeman's book but it appears they neglected to swap the dates and locations. The entry in the first edition agrees with the information in Hopson and Tobin i.e. Closed 1883 and 7km from Narromine:

It was certainly close to Narromine.
From Australian Handbook, 1885:

Located on Google Maps:

I wonder if anybody can locate the source used by Hopson and Tobin for this closing date?
At this point I am not convinced that the canceller was only used for 5 months in 1883.
The 1884 Newcastle city and country almanac & directory shows mail deliveries to Ballast Siding at 6.30pm:

As for the suggestion that it might be 1150 of Walcha Road, the aspect ratio of the frame around the numerals does not match 1150. 1150 has an aspect ratio (width to height) of close to 2.0 while the cancel under investigation is closer to 1.7 as per others in the 1160's such as 1162 and 1164.
In addition to the aspect ratio, the curve of the top of the 6 is quite obvious and the sloping upright of the 5 is not present, rather a more vertical upright as per the 6 of 1164.

It's also strange that the post office would close five months after opening and a couple of months after a new school was announced for the area:

It's interesting, as Rod222 mentioned, that the village of Narromine was gazetted in 1883, having had a post office established in 1882 after the arrival of the railway.

From
http://www.mrl.nsw.gov.au/LocalHeri...ine-timeline:
1882: William O'Neill was in charge of the first official Post Office. The Railway from Dubbo to Nevertire was formally opened on October 10, 1882. The Railway Station (the oldest government building in Narromine) was constructed.
1883 The village of Narromine was laid out in 1883. The first school was opened, Mr H. Townsend was headmaster.
1884 The first auction for town allotments was held in Dubbo.
1885 The village of Narromine was proclaimed.
1889 A police station was apparently first established at Narromine with one constable.
Was Ballast Siding consumed by Narromine?
Is there an official document that shows exactly when Ballast Siding post office was closed?
Was the numeral 1160 canceller used somewhere else after Ballast Siding?
I'll try and find out more about the interesting history of these settlements.