From what I can see the printed copyright Jill Barklem 1985 refers to Jill Barklem, the author of the Brambly Hedge books who "worked closely with the designers at Royal Doulton to create this adorable pattern. Royal Doulton Brambly Hedge was produced from 1985 to 2006."
So 1985 was the date the collaboration started and would not refer to when particular pieces were produced. The boxes would tell you that but I doubt it is really important as all are apparently discontinued. It is not something I know anything about but there are a large number of items listed here
http://www.collectiblescoach.com/2015/04/royal-doulton-brambly-hedge-price-guide.html
Prices may be very fanciful for all I know. There is certainly a fair bit of it for sale and some of it even sells.
