Hi Ron,
Thanks for posting. Great pictures - Do you have any others of the local area?
Although the wooden chicken coops are indeed long since gone, if you were to visit the site now you probably would not see a significant change.
The Canham's farmhouse is still there, although very little is now standing - it has been derelict for the past 40 years or so.
The glasshouses of Marshmoor Nurseries have all disappeared and have been replaced by a caravan & trailer business.
The only real change has been the addition of a residential park home site - Marshmoor Crescent in the centre of the site
http://www.berkeleyparks.co.uk/parks/marshmoor-crescent/UNFORTUNATELY this is all about to change. The various land owners and the local Council are intent on destroying this attractive rural buffer to Welham Green and have recently voted through a proposal to build 80 dwellings and 4.1 hectares of industrial work units as part of the proposed Local Plan for Welwyn Hatfield.
It was interesting to read your recollections on the SAHAAS site -
http://www.stalbanshistory.org/page_id__428.aspx I have attached the proposal from Lord Salisbury's Gascoyne Cecil Estates (one of the landowners) for Marshmoor below.