The 1972 SM 2 sold on BAT for $US 35k last week. Will be interesting to see what this SM sells for. I prefer the look of the two door over the four door. https://bringatrailer.com/listing/1972-citroen-sm-29/
I prefer the front grille of the '72 over the '73. The rust will be problematic so I doubt it will fetch the same price as the '72.