I understand "a dodgy con artist" as "a tricky artist who imitates the work of famous artists and sells the imitated as true for money." Am I on the right track?
Before becoming possibly the richest man in history (taking inflation into account), John Rockefeller was the lowly son of a dodgy con artist and high-school student in suburban Cleveland, Ohio. Although he had some education, by the time he was sixteen, Rockefeller decided it was time to shirk school and begin a career—with the goal of earning $100,000 in his lifetime.