Joe,
Original exhaust manifolds are an example of what street rod builders throw away. With some sniffing around you should be able to find that part for just the cost of postage, While the manifold is off might be the time to make the shaft and some bushings for the manifold from stainless steel. I did that on my '36 Chevy PU about 35 years ago and it totally cured the sticking shaft problem.
