Australian Gen Serv buttons selection

[GTB]

Am posting a small selection of mainly AMF buttons mainly for comparison purposes, however I would be pleased if I can be provided help in dating.

Top button is the version with state lines on the map. 'K.C. Luke Pty. Ltd. Melbourne', gilding metal.
2nd row is by far the most interesting button (to me). The coastline is finely and sharply delineated, unlike the normal contoured rendering. It is also the only button with the old-style of KC whereby the upper pearl arch is straight, as opposed to the usual curved arch. The bz buttons further down are close to being same style. Backmark: 'A.J. Parke's. Brisbane', brass.
5th row, oxidised copper
Bottom row: (a) 2 RAN buttons - The gilding metal button in bottom row has backmark 'Kitchener Ltd Sydney'. (b) Australian Commonwealth ERVII l & s; (c) ditto GRV

GTB