https://www.chicagotribune.com/news/...221-story.html
I guess spoke maybe too soon, i fopund some more info:
Excaliber cars-how many were built ?
from "cobraduke" CC member quote about side pipes (2011):
"In the process of upgrading to proper headers and side pipes to uncork it. Bob Bennett of Bennett Coachworks in Milwaukee is almost ready to start producing a complete bolt on header/exhaust for the Excalibur. Web site is Milwaukee WI Hot Rod Builders | Auto Restoration Services | Vehicle Updating | Bennett Coachworks. Knows these cars from preproduction days."
and : "guy in Oregon, "Pacific Roadster (Salem Or)". He will be duplicating the side pipes for me soon for a reasonable price"