A couple years ago, I was curious about the same thing, so I did a little search.
Here's what I found from the apocryphal Acts of Paul and Theclas
‘And he saw Paul coming, a man little of stature, thin-haired upon the head, crooked in the leg, of good state of body, with eyebrows joining, and nose somewhat hooked, full of grace: for sometimes he appeared like a man, and sometime he had the face of an angel.’"
If you look carefully at the WT's depiction of Paul, he always seems a little bow-legged.
But, of course they couldn't admit that their frame of reference came from an apocryphal work, could they?
Tee hee hee.
Incidentally, Theclas is a woman.
Another tee hee hee.
Sylvia