OK thanks. Going back to the first specimen - the colour is looks awful! However, it has a rather ragged flan, with what look like flan cracks. These are not seen on the other specimens.
In hand, with a glass, I think it would be possible to see whether these are real cracks, or just casts of cracks. That would be interesting.
Nearly 40 years ago I was introduced to an old man, who, as I recall, smiled and said to me, "Find me a collector like Colonel Horton"........
Rob T