I think the W stood for Wanky.
This helicopter could be the cover picture for the next edition of "The Worlds Worst Aircraft".
If these clapped out old piles of corrosion are worth ₤100M, then those old Wessex that were for sale must be worth at least ₤60M!
There are few aviation products in history that have had their Certificate of Airworthiness revoked at the request of the manufacturer. A sad page in the history of helicopters!