I do have more and will share. Would be good to know exactly what year and one of the Old Merc guys should be able to pinpoint by the models on display. I want to say 57 or 58 although I dont see a Mark 78 which I believe was new in 58.
Notice the steering wheel mounted on the display board which E.C. patented in 57.
Also Speedliners had fins in 58 and these are finless?
I have hi resolution scans of the photos which I can send to you.