There are at least two different versions of the Williams Dreyfuss Hudson, possibly three or four. The earliest versions look OK but do not have a great deal of detail. The drive systems incorporate a plastic universal joint that is somewhat weak and can break if it is overstressed. Later versions have a lot of fine detail and a much more robust drive system. I currently have one early and one late version. Both of them have flywheels, but I have been told that there was yet an earlier one that did not have a flywheel. This is hearsay; I cannot confirm it of my own knowledge.
The late version of the Williams Dreyfuss is worth much more than the early one, probably about double. I'd say a late one in perfect condition might be worth the $400; an early one more like half that. You really need to know what you are getting before you let go of your money. One quick way to tell from a photo is to look at the valve gear. The late version has a complete scale valve gear; the earlier one a simplified version.
Both of mine are currently under repair and will be on the Buy/Sell Board when I am satisfied that they are as good mechanically as I can make them.
