|The overprint is not too bad, but it is on the wrong stamp, a one penny 2nd sideface!|
The right stamp, but the overprint is the wrong way. The lettering should go from bottom to top, not top to bottom. The cancellation is also a forgery and does not look anything like the original. Auctioned in 2009 as a forgery here.
|Another forgery with the lettering in the wrong direction!|
The letters are in the right direction but the numerals are too thin and the bottom half of the A is all wrong. Offered for sale on Ebay
Forgeries are also known on cover where an original ½d overprint has been affixed to an original cover. To pick up this type of forgery would involve some knowledge of Queensland postal history.
An article on these forgeries can be found here.