Info on a Rockel hat please

[fxstc]

Hello - I would really appreciate some information regarding a Rockel hat that was my deceased fathers pride and joy.
I never was allowed to touch it even when I was older as it was so special to him and I would like to know why it was so treasured?

To start with I know nothing about hats so I will try and describe it the best I can - I will also supply some photos I have taken of it.

1/The style is??
2/What year it is ??
3/What its made of??
4/It is a dark blue with another shade of lighter blue in it which makes it take on a shimmering appearance - its tricky to describe so hopefully the photos will help?
5/It says it is a Rockel Echler Haar - what does all of that mean? - I know that the maker was Rockel, but what does the rest mean?

Thank you for your help.

 

[jeffgarf]

Hope this is not too late for the OP, but Echter is original and haar is hair, both in German. Haar usually denotes rabbit fur. Rockel closed down back in the 80's, but clearly this is an older hat than that.