Silver or not?

Hi. I've bought several first day covers with coins in the cover. When I lookup the coins here in the catalogue the only matching coin I can find is silver. However, my assumption (at least in some cases) was that the coin was CuNi. Two examples are coins identical to:

https://en.numista.com/catalogue/pieces44743.html (including identical colourisation)

https://en.numista.com/catalogue/pieces67909.html

Are these really likely to be silver coins or are just standard variants of the coins missing from the catalogue?

Hi,

Unless the coins came with some sort of COA to say they're silver, I'd say they were CuNi.

The Jersey £2 has a CuNi equivalent (KM#97)
http://www.ngccoin.com/price-guide/world/jersey-2-pounds-km-97-1996-cuid-30109-duid-89873

I'm guessing the Gibraltar £5 is a Westminster Collection £5?
In which case yes, they do CuNi versions of the silver £5 coins.

If the coins are in cover folders, they will either say "Silver Coin Cover":
http://www.westminstercollection.com/p-N655/Prince-Georges-First-Birthday-Silver-Proof-Coin-Cover.aspx
or "Commemorative Coin Cover"
http://www.westminstercollection.com/p-N725/Battles-of-the-First-World-War-Commemorative-Coin-Cover.aspx
to distinguish between silver or not.

I have been pondering over both of those for a while along with some others in relation to WW2, those particular two they have always been advertised as silver proof that I have seen.