Hello, below is an image of the mark on the silk of a spoon box supplied by Dyson & Sons of Windsor.
Note, the silk likely said "Windsor & Eton", but they are like twin towns facing each other across the river Thames and there only appears to be the single jewellers shop at 9 Thames St. The silk has the "Royal Crest" and by appointment. They seem to have had a royal warrant as clockmakers and jewellers to the Queen (Victoria). There is a barograph in the Royal Collection Trust supplied by Dyson & Sons.
"AG2012" commented on the business's music division and I think 2nd half of my image maybe the photo posted by "AG2012" which has now been lost. I found on a "Piano" forum that Dyson & Sons were tuners to the Queen & Royal Family and were retailing (pianos?). A Thomas Dyson founded 'Dyson and Sons, pianoforte dealers' in Thames Street in 1865 and he became Mayor in 1890. It is not obvious when the jewellery part started. Dysons sold plenty of souvenirs from their shop you can easily see on line examples of "Goss" china crestedware they apparently retailed.
There are not many of Christian names to go with "Dyson & Sons" the Jewellers. I found one, a "Cyril", later Sir Cyril Dyson who seemed also to have been a Windsor Town Mayor and a "Geoffrey" who was his son. A lot of this was in the post WWII period. There was also another "Dyson" Frederick (again later Sir), also a Mayor of Windsor for periods before and after WWI but I found no on line information to positively connect him to the Jewellery or music business. Around the late 19th and very early 20th centuries there are "London Gazette" references for Dysons as music sellers. The jewellery business ended in the 1980's.