The date is almost certainly after 1965 if gilt is present on the rim (before this it appears that the Carnival range was ungilded) - beware those items were excessive wear has almost completely removed the gilt!
However, if the 'straight' edges are slightly curved, and the corners are much more rounded this suggests the later shapes, making it post-1970. This one does appear to date from this era.
If you're going to Big Brum tomorrow Keith, I'll be there with Patricia from 7.30 (keen, huh?)