Carlisle has always been in Cumbria (then Cumberland).
There are quite a lot of old Wills for El(l)woods bet 1661-1750 - Wills proved in the Consistory Court of Carlisle, including the following in Dufton:
Agnes wid Dufton 1678 W
Chris, yeo, Dufton 1676 W
Chris yeo, Dufton 1698 W
Edmund, yeo Dufton 1710 W
Edmund, yeo Dufton 1730 WI 437 (56)
Edw yeo, Dufton 1677 W
Lancelot, Dufton 1683 AI
Mark, Dufton 1739 WI 49
Mark, 1658 Dufton (I have a full copy of this will if you want a copy please PM me)
Thos, Dufton 1665 WI (138)
Tho Dufton 1744 W 217 (136v)
Wm Dufton 1671 AI
AI = Administration of goods, Inventory
WI = Will, inventory
These are all held at Cumbria Archive Centre, Carlisle, I would have thought you could email them and for a small fee they could send to you.
With the Yeomen - it's possible that there will be Manorial Court Records for Dufton which survive and will give details of land transactions, property etc. It may be worth checking on National Archives website, to see if these are held at Carlisle or Kendal Archive Centre.