In response to your query regarding "replacement" VCs, the short answer is yes, there are such things as "official" replacements.

I have long been interested in VCs because of my service in the Canadian Armed Forces where I came into direct contact with several living VC honorees. I undertook to confirm the location of Canadian VCs some years ago and have attached for your information (as far I know) a complete record of where VCs are that were awarded to "Canadian" recipients. Note that the definition of "Canadian" varies between authors and my list includes all of the "Canadian" honorees noted in any published list - although they may be excluded by certain authors.

You will note in the list that there are at least two replacement medals that have been displayed in Canadian museums when the original medals were stolen.

As far as I can tell, the replacement medals are made from the identical materials as the originals (i.e. an alloy containing some of the metal from captured cannons from the Crimean War. I direct you to a website link below for more information on the manufacturers of the medal (Hancocks & Co. Jewellers in London, England).

www.hancocks-london.com/vc_manufacture.htm

Most people do not realize that the medals are actually cast and not struck from dies.

Although, I don't know the specifics, I have been told that the replacement medals are marked as such in some manner to distinguish them from the original (just in case lost or stolen original medals are recovered or found).