On the other hand, he later built the red '69 Mustang and again used a Willys frame. I guess he went with what he knew would work. The Multi-Maverick used a fabricated frame but that car only saw testing, it never turned a wheel in competition.
The Peanuts LTD body was fabricated by Kellison for a Ford commercial. It had no interior, it was made to be airlifted and set atop a mountain for the commercial. The interior shots were done later in a studio. Kellison kept the body after that (Ford only needed it for the commercial) and it later wound up on that funny car. I've actually done the four-door hardtop conversion on a '65 body...another one I need to dig out and finish...
--Mark