69 Barracuda Vinyl Roof Trim

Looking to install the small 3/4 vinyl roof on a 69 fastback. I have the trim pieces but am not sure how the trim is fastened or where to locate the fasteners or clips. I have checked the local on line sources and at Carlisle and was told they are a welded stud?? Anyone ever done one of these from scratch and might know where to locate the fasteners? Thanks for info.