help w/headliner install 69 AMX

Its the one piece fiberglass from Kennedy American. Got the old one out and cleaned up the roof, then installed some insulation- the original just had a small square of foam in the middle. Got the new one in, but was trying to decide how to proceed. Was thinking I can have my helper hold it up while I install the removable (w/locator pinsmetal) side channels- thinking that will hold it up and make sure its centered, but now to center it front to back? Thinking I'll just have to get the front edge up close to the edge of the glass and then check the back- and adjust if necessary. Now finding the holes for the visors and coat hooks will be trick- hoping someone can offer some suggestions. I have marked the bottom hole for the coat hook and visor BELOW where they actually are, since that area will be covered up by the headliner when its in place.  Thanks, George

Day 3............... It appears this one piece plastic headliner has some extra all the way around. Its a jagged cut and it WONT fit in the side rails so we can adjust it from front to rear. We tried bending it some but its  already bumping up against the metal roof reinforcement cross piece so there is just no place for it bend. I'm planning to cut a 1/4" off the sides (front section only that drops in the metal rails). These cuts will not get into the ribs of the liner and there will still be material angling downward to drop into the rails. Not any cut on the rear side section that appears to only butt up against the plastic rails over the wheel tubs. We may end up having to take more than a 1/4" off those sides to get it to fit inside those rails, and will most likely trim up the ends too as they appear to be in the way of getting the cover molding back on. Once its in the grooves on the metal rails, it looks like it wont be too much trouble to get the visor screws started, but its NOT EASY, didnt remove the seats and hope I dont have too. 

Trimming fiberglass is best done with a mini grinder with a thin cut off wheel, and not a saw. The saw will leave shards and no clean edge, possible to crack thin sections. The grinder can also taper were needed to get a better fit. Don't go too aggressive and heat the material. 

THANKS TO ALL, AND i AGREE that is sure looks like there is extra material all the way around. and yes, there are dimples for the visors- although I'm not sure they are in the exact location they need to be. I do have parts of the old one that I can use to check the width of this one- again something I didnt consider. Looks like I will be taking it back out of the car. george 

I can somewhat understand the aftermkt adding some for safety, but they come w/NO instructions- thinking that would be a good idea: MAY HAVE TO TRIM!