Had another look at the clear copy of Douce 1.72 on the Bodl site and I'd say this writing was most likely 18thc but I'm no expert on handwriting. Incidentally there is another copy in Douce printed in the early 18thc which corrects 'channel' to 'chancel'. I also got the 'Black Letter' wrong. It's printed in italic, but the cuts are definitely 17thc. I spent a day in the BL this week looking at the Roxburghe and Luttrel sheets and some were printed by Bates. I'll check my notes and see if I can verify Sarah Bates' dates.