Ian & Sue - I don't understand the reference "02689" - that isn't a Sowerby number. 2689 could be, but as all Sowerby numbers were issued chronologically, that would have been well after "my" time. I left in 1957 or 1958 and I think we were then up to around about the high 2650s.
Colours did vary a bit (I plead guilty!), but especially pink - a real swine to keep dead constant.
I don't think I have mentioned it before on the GMB but, apart from technical stuff on chemical compositions, I have zero records of Sowerby or Davidson. Everything is in my head - although, as everyone knows, all stuff learned up to the age of 25 or so sticks pretty well, thank goodness. However, I can now confirm that things like some of the less used pattern numbers (NOT 2631!) can start to get a little fuzzy as one approaches 80!
Adam D.