Origin of the Germanics in Jastorf Culture Area?

[Hagogoth]

It is assumed that the Germanic people and culture arose in the area of
Hannover-south of Hamburg-Berlin and north of Thuringha about 700 BC.
Maybe included Westfalen and Sleeswick-Holstein.

Who has read "Namenkundliche Studien"written by Juergen Udolph?
According to him the Germanics are in the Jastorf area. He excludes
Scandinavia and even Sleeswick-Holstein. Who can give me more information?
What was the relation between Scandinavia and the so called Jastorf area?
Which tribes did live in the Netherlands and Belgium? Who can give information about the words in the Germanic languages which did not have an Indo-European origin. It especially is a question of words in relation with
the sea and harbour.

[Walders]

It is assumed that the Germanic people and culture arose in the area of
Hannover-south of Hamburg-Berlin and north of Thuringha about 700 BC.
Maybe included Westfalen and Sleeswick-Holstein.

Who has read "Namenkundliche Studien"written by Juergen Udolph?
According to him the Germanics are in the Jastorf area. He excludes
Scandinavia and even Sleeswick-Holstein. Who can give me more information?
What was the relation between Scandinavia and the so called Jastorf area?
Which tribes did live in the Netherlands and Belgium? Who can give information about the words in the Germanic languages which did not have an Indo-European origin. It especially is a question of words in relation with
the sea and harbour.

I did not read the book, but as far as I know the West-Germanics were the people of Jastorf, which is part of the Germanic or Nordic Iron Age. The West-Germanics probably had a high influence on the North- and East-Germanics.