Australian 1954 1/2 Penny question

[Jello63]

Hi All,
I have finally had time to go through my coin collection that I have had for many moons. Amongst them I found a very odd 1954 Y. 1/2 Penny. It is silver? At first I thought it must have been coated at some time by someone, but on closer inspection the coating is way too professional looking. Is it possible to be a silver proof? I have seen from a dealer a 1955 1/2 Penny Proof in silver. Any help would be appreciated.

[Lightw4re]

Can you post pictures to show us the coin? Will be easier to identify.