I can tell you FOR A FACT that real high end body shops use lead not filler. Its heated and poured into the imperfection, then sanded smooth. The finish is absolutely perfect, doesnt shrink or crack and is undetectable. Coach builders have used it for decades because nothing can match it.
I used to work for bo huff in Utah and he always said " if you need Bondo you are doing it Wrong tho" and he showed me how to Lead and its all I have ever done.. the second I see Bondo in a Body shop I tell them to go else where its a lazy man's way of doing a job right.
Jessie was the "candy" that the eye of mechanics could see! I'm Glad she went out like she did, because she chased her dream! The rest of us should cower in her presence! Mucho Respect!