That's probably because most sources don't count examples from all factories
A number of ~680 pretty much covers only Fieseler Kassel factory production numbers.
FockeWulf 190D9 was produced in:
Focke Wulf Cottbus - 720
Focke Wulf Aslau - 30
Fieseler Kassel - 680
Wesserflug Lemwerder - 50
Mimetal Erfurt - 325
TOTAL: 1805
I'll try to scan the pages from the books tommorow so you guys can see production dates and werk numbers, I don't have a scanner at home
A number of ~680 pretty much covers only Fieseler Kassel factory production numbers.
FockeWulf 190D9 was produced in:
Focke Wulf Cottbus - 720
Focke Wulf Aslau - 30
Fieseler Kassel - 680
Wesserflug Lemwerder - 50
Mimetal Erfurt - 325
TOTAL: 1805
I'll try to scan the pages from the books tommorow so you guys can see production dates and werk numbers, I don't have a scanner at home