Hornsby engine was sold in the early 1920s. The mill was tailwinded c1920, and as a result one pair of sails was removed. Vincent carried out some repairs to the mill and ran it until he retired in 1924. One of the remaining two sails was wrecked in 1926 when the mill was again tailwinded. On the death of Alphonso Vincent in 1932, his son George inherited the property. He lived at the site in an old lorry until his death in 1973. The mill passed to his daughter, who sold it in 1974 to Mr and Mrs Humphries, who intended to convert it into a house. They later changed their minds and offered it for sale for restoration. In 1976, the cap of the mill was blown to pieces in a gale. Thelnetham windmill was purchased by five members of the Suffolk Mills Group in November 1979, and plans for restoration were made. The consortium consisted of Mark Barnard, Charles Dolman, Peter Dolman, David Pearce and Chris Seago. The derelict mill and an acre of land cost £6,000. In 2013, the mill was gifted to the Suffolk Building Preservation Trust, which also owns Pakenham Watermill. On 14 July 2019, the bicentenary of the windmill was celebrated. The Locomobile lorry that George Vincent had lived in, now restored to its original army condition, was present. Also in 2019, the mill was used as a polling station during the European Parliament election in May, and in the General Election in December. The usual venue, Thelnetham Village Hall being unavailable due to it undergoing a major refurbishment. Restoration The mill was restored over a period of six years. Much of the work was carried out by enthusiasts who used working holidays to repair the mill. 1979–1980 The consortium took possession of the mill in November 1979. The first priority was to make the mill as weathertight as possible. Polythene sheets were spread on the dust floor of the mill to prevent further water penetration of the structure. The mill was surveyed and recorded. In spring 1980, the dust floor partially collapsed and was removed as a safety measure. Scaffolding was erected to allow the fanstage to be dismantled, and the cap centering wheels were removed in preparation for the removal of the cap frame. A two-week work-in was held at the end of July and beginning of August 1980. Thirty-three volunteers worked