I am the researcher who has done the most extensive research on the Mull Bridge.
A copy of it is held in the Hayes Liubrary in Fremont, Ohio. I grew up less than 2 miles from the bridge, and my father was the caretaker/trustee for it through the Sandusky County histroical society. George White of Clyde is famous for his oil renditions of the bridge. I own one of his originals.
Dottie(Ziegler) Linn
Bowling Green, Ohio