I have a brochure, I think I got it in the early 1990's, "Nettleham Engineering Co. Ltd" whose address is Britannia Works, Beaumont st. Gainsborough.
The cover has photos of an impressive old road frontage and an aerial shot of what appears to be an intact large works.
I presume this is Marshalls old works?
They were advertising themselves as the UK's largest machine tool dealers and there are impressive photos of tall halls full of machine tools.
I kept the brochure, hoping to visit one day....
Old Glory #48-51 has a history of the Marshall MP6 tractor. It is a bit erratic, but it covers some of Marshalls past history, but nothing I recall about what came after the MP6.
Michael Lanes Fowler history says Fowler and Marshall merged in 1946, but that Fowler became largely passive thereafter. When he wrote his book (1980), Aveling & Marshall Ltd were still trading as part of British Leyland, selling crawlers, road rollers and other 'special equipment'
I have just bought a little booklet "The Rise and Fall of Aveling Barford 1933 to 1988", published in 1997. It says that they were still trading at that time as Wordworth Holdings, but still had an A-B division.
I am interested to hear any of the recent history of Marshall too!