2nd chair to identify please  

@onatelenet-be  Are you familiar with Google Lens as tool for searching images?  Both of the chairs you posted return many examples using this tool.  This one is attributed to Ico Parisi for Malatesta and Mason, Italy, 1950s by the ones I saw.  The other chair you posted is attributed to Pozzi and Verga, also Italy, 1950s by a number of sources.  I don't know if these attributions are accurate, but it gives you a place to start researching.    

@mark737. Found the same info myself using Google lens. Did a very quick search for catalogues/ print adverts . No luck. Will do further research ....

Thank you, Mark and Lexi, great help!