Hi there
Tricky to date a scarf because there's not much to go on except the label. I can say it's no later than the late 90s, as that is when Burberry dropped the S from their name.
Giving detailed fabric content (100% lambswool), and care instructions (Dry Clean Only), suggests to me it's probably in the 1980s to late 1990s time frame. If you look at the VFG Burberry labels timeline, '100%' starts appearing in the 1980s.