Try this: http://www.jalopyjournal.com/forum/showthread.php?t=205775&highlight=model+scans Hopefully there is something there that will help. Not sure how much deth you need to go to.
My Father and Uncle started on an "A huckster" project a few years ago. They did buy plans which where easy to get but they got a lot done in the mean time while waiting for the plans to arrive by just getting out in the shop and going at it with with wood and an A cowl.
That would depend on whether you wanted to actually build a 28-29 Woodie Station Wagon or some variant of a huckster or hotrod 2door lumberwagon.
He is "woodguy@woodieworks.net. Built my old '32 woodie roadster pickup and a bunch of other 2-door phantoms. He's in Cincinnati, but does not have any plans, but his web site has lots of great photos for ideas.