from boge to bilstein: need help

[Konstantin Bogach]

Hi listers.

I am changing rear struts. Old ones are BOGE, new - Bilstein. I feel
like I miss something.  ETKA shows bump stop bearing which serves as
bump stop lower seat.  Old strut does not have any thing like  this. But
it has top of the body looking like concave washer.  This concave seat
helps  bump stop to stay away from assimetric deformations. There is
convex washer on top of the shaft, right under rubber damper ring. From
other hand there is no lower(concave) washer showm in ETKA.  Maybe this
washer is not a part of the strut body but is what is called bearing in
ETKA?   Does anybody know whether it is removable?  And how if yes?

Thank you.

Konstantin Bogach.
200tq '89
200tqw '89