Yep, you've said it all Mike. Without "handling" it, it is difficult to say from the photo if it is fake or not!
The easiest way to tell them apart is using the colour as a guide, the reproductions are not in Whitefriars colours
In the case of the fake "green" it so happens it is a very good colour match for Whitefriars Meadow Green.
Some of the fakes have a letter "V" scratched into the base, others do not. Mostly they have a moulded and slightly "wonky" pontil mark, rather than a ground and polished one.
The price paid for this one under discussion was very cheap if it is genuine, usually go for Â£150 ish............so suspect that it was considered by the collectors of these onions (I am not) that it was fake.
As a matter of fact this seller is "peculiar" to say the least, and several people I know are keeping an eye on him for various reasons.
As for getting any compensation for this seemingly bad purchase, I think that is impossible as the listing was innocuously written, as indeed most of his listings are.