Vintage Christmas tree lighting set.

I have used this set of Lights for many many years, so long ago in fact I can not remember not having them. I am seeking help in dating them if possible. There is very little info on the box except Made in England. I think they were bought in Woolworths, might be late 1930's/40's. I can remember that my Father was in charge! until they passed down to me in the 1950's. HELP PLEASE.