Once Dawn has 3 posts she can use PM to exchange email addresses since they are not allowed to be placed on the threads.
Remember that any census just shows the details of people in the household on one particular night so it may just be that your grandfather was staying away from his normal abode that night.
My grandmother is listed in one census twice (once with parents where she normally lived and again with grandparents where she was staying for a few weeks), her cousin (with wife and child) is listed three times in another census and in the 1991 census my parents will be show in my house (even though they live in another country) because they were over visiting at that time.
