Hello Oliver,
Your Grandfather is buried in Riverside Cemetery, Port Arthur, Ontario. PW section lot 2.

You may obtain the book here.
[members.memlane.com]
David Carter who I think is still going strong, may be able to help you with what is available in the Canadian Archive in Ottawa. His e-mail address is on the website.
As regards Crew lists in the British Archives. I think the chances of finding details are slim.
Nearly all of the documentation relating to German POW's was transferred to Germany in the 1950's and I think are maybe in WASt
[www.dd-wast.de]

Good luck in your quest.
regards
Roger.