I'm still looking at the details, but it looks like the correct Johann Wichard is Brümmer-545, an uncle who first had a family in Menslage, and then seems to have moved to Amsterdam to marry Femmetje Alyda Soost in 1771. In 1794, his only surviving daughter, Maria Adelheit, also married in Amsterdam.
This Johann Wichard was born in 1721, which means he 'improved' his age at marriage in 1771, stating that he was 40 years old.
I will first add this information to my private Gramps database, and then upload the pictures, together with those for the baptism of their children in Amsterdam.
I've been updating my list of Menslage Brümmer ancestors, and once that is ready, I think I'll update all my additions using a gedcom compare, in one big go.