3D Modelling Chair

Hi,

I would like to have three adapted 3D models of the panton chair.
You can download the 3D-Object here
https://www.modelplusmodel.com/furniture/chairs/0225-chair.html

Those three chairs should be like:
1. the width of the chair should be doubled (for two persons)
2. the width of the chair should be tripled (for three persons)
3. the chair should transform to a half circle (so more persons can sit on it)

I need to open the final models in freecad

thanks for help