There are dozens of them in Melbourne. Do a search for "Coin Dealers" in the Yellow Pages.
Here are a few based in the city -
Downies Town Hall Coins
Shop 11-12, Block Arcade 98-100 Elizabeth St, Melbourne VIC 3000, Australia
Max Stern & Co
Port Phillip Arcade, 234 Flinders St, Melbourne VIC 3000, Australia
Peter Strich Stamps & Coins
Emirates House Shop 5/257 Collins St, Melbourne VIC 3000, Australia
Mowbrays Australia Pty Ltd
Level 1, 422 Little Collins St, Melbourne VIC 3000, Australia
Noble Numismatics Pty Ltd
Level 7 Citibank Centre 350 Collins St, Melbourne VIC 3000, Australia
Universal Rare Coin & Banknote Company
Wales Corner Building, Level 10 / 227 Collins Street, Melbourne VIC 3000, Australia
Any reputable coin dealer should be able to value the coin for you. Look under "Coin Dealers" in your local Yellow Pages.See the link below.
Do a Google search.
You could try eBay or a reputable coin dealer in your area.
A reputable coin dealer will be able to value your coin. If the coin has been circulated, you might be lucky to get 50 pence for it.
Bring it to a reputable coin dealer and they will identify it and give you an opinion on its authenticity. Most coin dealers will not charge you for this service.
You could take it to a reputable coin dealer or advertise it on eBay.
There is no documented evidence of a minting flaw in the "Festival of Britain" Crown, but it is possible. A reputable coin dealer will be able to advise.
You could try a reputable coin dealer in your area or eBay.
Your best bet would be a reputable coin dealer. Alternatively, you could try eBay.
You could try a reputable coin dealer in your area or eBay.
Unless the coin is mint uncirculated or Proof, you are not likely to get much for it. You could try a reputable coin dealer in your area.
These coins do not have a minted value and do not appear in coin catalogues, but they are collectible. The only helpful suggestion I can make is to take it along to a local reputable coin dealer for valuation.