I'm in the process of shaving the drip rails on a '68 Camaro. I have a blog explaining to process if you want to check it out. customcarupholstery.blogspot.com

 

I did that on my '69. the problem was that the roof was so old and the edges weren't in that great of shape, that everytime I went to weld, it blew through so I had to go back further to get solid metal to weld to

most people just cut off the drip edge and weld the seam so they don't have that problem, but I left none of it at all, so there is zero seam there at all