Cathy - this is such a wide ranging and almost impossible te answer topic, isn't it? I've been thinking along much the same lines as you.
The first notice we got of the Crown Crystal fakes was from a (so far) anonymous source stating that all the moulds were in China and were being faked. This is not proven, and could be groundless.
The first factual info was the photographic proof of Kingfisher nappy (small berry bowl) items appearing on Australian eBay (as in the recent one you showed us from April) and the photo someone sent to Dave.
Carnival collectors in Australia have confirmed that the small Kingfisher berry bowls have been seen at auctions. They are very clearly faked and there are several versions. They wouldn't fool anyone who has seen the originals.
The big problem is...are any other CC pieces being faked? And the answer is, I don't know. If they are, then they are VERY GOOD fakes.
Did the original moulds survive? Possible. But I sort of doubt it.
What are other Carnival fakes like? Well, the main ones to consider are the Far Eastern fakes of the Northwood Peacocks, Good Luck and Grape and Cable. They certainly don't use the original moulds. They have simply copied from the glass items. They are easy to spot if you are experienced. Not so easy if you are a newbie. On some there is a large N mark - and it's a dead give-away!
There have been several generations of the N fakes, over maybe a decade or two! You can see some here.http://www.geocities.com/carni_glass_uk_2000/FakeGCable.html