I am an absolute beginner at reading hallmarks. My understanding is that this is a silver case made by Rolex and the sponsor W and D. The mark 925 and t are UK marks and denote sterling silver and the year of assay as 1914. The “omega” is the London office mark for imported silver/gold/platinum. The number 606683 is presumably the case number. What do the numbers 60 and 1 mean and who are W and D?