The car is the 1954 Ferrari 750 Monza s/n 0470MD, here at Swedish GP in Kristianstad on 12 August 1956.  Drivers are (from left): Carl Lohmander, John Kvarnström (owner of car), Jo Bonnier and Juan Manuel Fangio. (Rightmost person is unidentified). Source of this info: <a rel="nofollow" class="external text" href="https://bilsportarvet.se/2013/10/en-bild-sager-mer-an-tusen-ord/">En bild säger mer än tusen ord</a>, Janne Tromark, Bilsportarvet, 10 October 2013. The picture was given to Tromark by Lohmander, but it must have been taken by someone else.
Unknown photographer
<a rel="nofollow" class="external autonumber" href="https://scontent.fsvg2-1.fna.fbcdn.net/v/t1.6435-9/218634114_284493870136241_8044392139555547233_n.jpg?_nc_cat=102&amp;ccb=1-4&amp;_nc_sid=730e14&amp;_nc_ohc=qbxvQ4SEmCgAX835l_9&amp;_nc_ht=scontent.fsvg2-1.fna&amp;oh=7a7f6248b7fb2face785463fb1bd0b9a&amp;oe=6137C7FC">[1]</a> (Bilsportarvet)