Cooper, in that photo, is leaning on a full size Phaeton. The Gable picture I attached was another (different model) Duesenberg, not his SSJ.
Without referencing the Duesenberg books, the SSJ model Duesenberg were the model that only 2 were manufactured ... one for Gary Cooper, the other for Clark Gable. Clark Gable's was 1 foot longer than Gary Cooper's.
Of other famous owners of Duesenbergs was Tom Mix who owned several and died in a "sister" car, a Cord, in 1940. (ref: "sister" Cord / Auburn / Duesenberg )
Here are the 2, famous, SSJ's:
Model SSJ
Whether it be the RM of either Clark or Gary, or the Duesenberg(s) owned by either one, be prepared to plop down some serious cash.
I believe the same owner of Gary Cooper's RM also owns Clark Gable's RM.
Back about 30 years ago I went on a quest to find Clark Gable's RM from a 1981 auction catalog when it was sold. After several years (the pre-internet days) ... I tracked it down. I wrote the (then) current owner twice. I did not get a response to either letter.
Both Cooper's and Gable's RM were on loan to the NRA museum IIRC, also Jimmy Stewart's. Correct me if I've misstated any of the above.
Oh, I researched to find Gable had the Gullwing coupe. Did not know Cooper had one, too.
Yes, just found online ... only 2 SSJs were made, one for Cooper, one for Gable ... see:
The Clark Gable 1935 SSJ Duesenberg in Los Angeles | The Old Motor