I am fully aware of market theory, but am a little puzzled as to why the silver herringbone 58 is seen as the most expensive Conway. Of course, it is rare, but Jonathon has sold many pens lately that he claims(and is no doubt correct) are the only ones known to exist and they dont bring excessive prices. Any ideas?

I doubt that the silver herringbone 58 is actually THE most expensive or rarest vintage CS, though it would be towards the top of the list.

The Lambrou effect is in operation here. It was his books that pronounced only 200 floral 22s were produced and that the silver herringbone 58 he pictured was the only one known. These facts get ingrained, especially if you are not a dedicated CS collector and don't know that our knowledge has moved on, hence the ridiculously high prices for the 22.

Even Jonathan is at fault occasionally - some of the numbers he claims are the only ones known do actually exist in other collections, it may just be that the owners didn't bother to inform Jonathan!

Even so, there are lots of CS model numbers (and / or patterns) that are only known as one-offs. As there are very few people committed to collecting all possible model numbers, it is the general desirability of the one-offs (based on colour, pattern and condition) that will affect the price, rather than the absolute rarity.

Andy