Thanks for the advice guys, Macs is sending us a new headliner so for now I just have to be patient and keep researching tips for installation. In the meantime I've been messing around with the current headliner (which we'll be sending back), just to find out the right positioning and where things tend to bunch up. I got a rough fit and it's looking a lot better. I'm hoping the second attempt goes smoother. I'll try to remember to take some pictures of the process and post them for everyone. If anyone else has some experience or more tips, please do share. Keep you posted.
1962 Ford Thunderbird Hardtop