The car could have been used as a backdrop to set his age - that model apparently first came out in 1960, and placing that in the image would convince you he was about two years old when that photo was taken.
That would eliminate any questions you might have - that he could have been born before 1960 for example.
If the bike was produced in 1960 it might have sat in a retailers showroom for how long? However, the bike is a better indicator, it’s real, he’s sitting on it, and it would be most unlikely that the bike itself wasn’t in the original photograph. (Unlike the vehicle.)
I could be missing something, but that’s as close to his age we are going to get in this instance...he’s two years or a little more of age, and he was born after 1960.
I would put his age 3 or slightly more. 2 years old and that big and riding a bike is little much. But a narrowing down of the bikes age would be good to have.