Medal - Governor of N.S.Wales, 1877

Am researching this item for my Dad.

From what little information I have discovered,

I know it is from 1877 NSW, Australia.

The head on the medal is of Hercules Robinson, Governor of NSW at the time.

I have a suspicion that it is from the 1877 NSW Exhibition?

There is another one at the Powerhouse Museum Collection

(That is where the photo is from):

http://www.powerhousemuseum.com/collection/database/?irn=308114&img=85476

Description Medal, awarded to Sir Hercules G. Robinson KCMG, Governor, 1877. Registration number N376-1

And it says that that one was actually awarded to the Governor

so I dont know if this was part of a collection given to him, or part of a collection made for the Exhibition and the Governor was Given one of the coins or what.

I am pretty sure that mine didnt belong to the governor but I could be totally mistaken.

Any infomation on history (or value) of this item,

what it was used for or given to, who it was made by -

anything at all really would be great!

Thanks :)