I don't know where you got your information that the senior Gibson was involved in the marketing of the film. He is almost 90 years old, and lives in West Virgina. Whatever your source, I am sure it is bogus, like so many things that have been posted here on this subject.
From Hutton himself. He claims to be involved in the idea of a "Vatican endorsement". He may well have been lieing. Unfortunately Nierob responded with a no comment to Hutton's interview, so we'll never know.
Why did the ADL oppose the film?
Gibson
This is part of their deal they don't want this movie shown they don't care if the movie is anti-Semitic or not, or if it is straight history. Mel says he absolutely couldn't buy PR like this. And (thanks to the ADL) everybody knows the line now: Let the blood be upon us and our children.
IX. The Pope & The Vatican
Steve Feuerstein
What do you aim to achieve by screening the film before the vatican Ð Why did you need the Pope's Approval?
Gibson
And anyway somebody said why do you suppose he (the Pope) approved the movie? I said what do you think he would say when it comes out and he disapproved it.
The ones that we have there (in the Vatican) are all involved in the (Jewish) plot. The need of the Vatican endorsement wasn't, it just wasn't needed at all. The only reason they went over is that the ADL had threatened to take the film over and show it to them.
They would have to steal it to do so they did already. One of the guys in the office said why don't we take it over to the Vatican and show it to them anyway cause they wanted to see it and they did want to see it. And Mel said "OK lets take it over and show it to them." They were not after any accolade. They just wanted to take it away from the ADL who was going to go in there and put some pressure on like they can and get a condem-nation of it.
No, no we had no idea of helping out the Vatican in any way. You see here we have what we call a hostile witness. As Mel said while they were on the way over, "What is he going to say is he going to condemn it because when it comes out he'll show what a big ass he is." What the heck could he say? The Jews were going to take it to the Vatican this was the argument from one his producers there, Steve McEveety. Mel said "Go ahead. Let us do it." The ADL might have even taken a few shots themselves and shown the Pope something that was not in the film. There is nothing these guys would not do