In reply to TheDrunkenBakers:
I was just about to recommend the Yorkshire Marathon to you!
Kielder is beautiful (I'm a Northumbrian) but more of a trail run than a standard marathon.
The oldest (?) road race in the world was resurrected last year as a Marathon from Morpeth to Newcastle but I think the logistics of Yorkshire will be better for you.
I missed out on London so ran Paris instead a couple of years ago and went from never running at age 42 to Half Marathon in six months then to the Full in Paris 6 months later. 1:57 for Half, 4:27 for the Full........not great but quite proud of myself.
I'm still running now 2 years later approx 15 to 20 miles a week, got the Reading Half next month.
Good luck with your op and share your training on here