I've been working on a project to identify all the Fasts in the 1776 census of Mennonites in West Prussia. Glenn Penner's extraction of the data is found here. My theory was that one or both of the parents of my earliest known Fast ancestor, Gerhard Fast #660202 (1739-1829) might be listed in that census, and I wouldn't even have known about it. His oldest known sibling was born ABT 1737 - if his parents were about 20 years old when their first child was born, they might have been born about 1717. Thus in 1776, they would have been about 60 years old.
There were 31 Fast families listed in the 1776 census, and 11 of them had previously been identified in Grandma. I was able to identify 11 more Fasts, so now 22 of the 31 are identified in GM.
My methodology was to look for them first in GM. Then I checked my spreadsheet in which I have extracted 431 individual records over the years from the Mennonite, Lutheran/Evangelical, and Catholic church books to see if I could find the person. I checked the Mennonite church books that Andreas Riesen extracted. I checked the 1772 and 1789 census, the immigration records to Russia in BH Unruh, Peter Rempel, and that I have gotten from the Prussian archives in Berlin, and the land records that Glenn Penner has posted online.
Unfortunately, none of the Fasts whom I was able to identify were old enough to be the parents of my Gerhard. There are 3-4 Fasts whom I could not identify who lived in the Gross Werder and are potential candidates to be Gerhard's parents, but I found no information to identify them. I was able to tie many, many children to the 22 identified Fast families, so I've added a lot to the store of knowledge about the Fasts in GM, so it's been a useful exercise. But I didn't accomplish the goal that I set out to achieve.
I'm planning a trip to Poland in 1-2 years to do research in the archives there, and this work was a necessary prelude to that trip. I wouldn't want to make an expensive trip to the Polish archives without having done everything that I could with data that is available to me while sitting at home.
I'll post the spreadsheet with my results in the near future, but I need to clean up the spreadsheet first.