To the best of my knowledge, '28-'29 didn't have a "fold down" posts but it seems that through the years, multiple sources have made up "hybrid" posts. Things get complicated because it turns out that the body I got is a bit out of kilter where the posts mount.Speedway has the dimensions for all three of the open vehicle windshields on their webpage. Why not use 1928-29 fold down posts - seems like it would be a lot easier?