Many thanks to Holmemoss and acorngenealogy.
Firstly can I tell acorngenealogy that I'm sorry he hasn't found the Willie Emmott I'm looking for. There were 2 Willie Emmotts born in Yorkshire in 1881 but "my" one went on to be a major force in the automotive industry and had an extremely impressive estate in Berkshire.
I said I didn't remember any details of the wills but I do know there were descendants and I believe one of them, a lady, lived in some style in Switzerland but has since died.
I had found the 1881 census record of Willie in both Ancestry and FamilySearch and followed him and his mother Lavinia through to 1901 where Lavinia is living in Lincoln and has a husband, George Henry Toon. I haven't found any record of G.H.Toon or Lavinia in 1911 but Willie is apparently still in Lincoln. I found no trace of a wedding for Lavinia but G.H.Toon was married in W Derby in 1896 - no record that I can find of Lavinia there - trust her to marry halfway between censuses !!
I've just found that I was contacted previously from Australia about this part of the Emmott tree but there were a hell of a lot of Emmotts in that little Yorkshire Village and a high proportion of them were tailors.
Anything more about the Shelley Emmotts and Willie, who becaome a millionaire, will be much appreciated.