Problem sorted!
I got it out thanks to mail conversation over the last weeks with Wolfgang at w113.eu,
I bought his conversion kit to install Getrag 265/6 from him, two years ago.
I used the method with bolt and nuts to press it out, see picture, good to know if someone else runs into this problem
The problem to get the Getrag out was that the cover of the crank bearing that had fallen out of position and got stuck in the chamfer between the splines and the end where the bearing slides on.
Now the gearbox will be sent to Hulleman in the Netherlands to be fully refurbished, so the 230SL can be ready for the spring.
Best Regards, Lars