There is considerable debate about Thomas Inch's film clip here:
British Pathe
Type in Tom Inch in the search box. Look for the clip called "Inch-By-Inch".
It is obviously not 100% legit. But he is clearly in the waning years of his strength performing career, and he is making a living off of his courses. Failure would not be an option in this clip. He had credentials when younger, and was indeed strong, I have no doubt.
Read more about him here:
INCH
What he did give us, was that friggin dumbbell that every grip nut dreams of picking up, and that's a good thing.