Take your hand and curl it around the inside top edge of the soft top compartment starting at the very front at the hinge area then continue to feel the inside curved area as you carefully slide your hand slowly around the corner adjacent to the trunk and on across to the center of the trunk. Repeat on the other side. I found mine to be considerably rough in the inside curved area with many sharp protruding edges especially near the hinges. I used a small abrasive metal cutting disk in a dremel tool to carefully grind away all the sharp edges so that the metal was smooth to the touch all the way. Finish with black spray paint then go to Lowes in their tape counter and you will find a wide black vinyl tape about 1 inch in width. Stick the tape all along the area you have reworked to give it a really smooth finish. Before you lower the top into the compartment lay a 1 quart size zip lock bag over each side at the hinge area (2 people work better at this) and as the top goes into the compartment it will slip very easily over the vinyl baggie.
My top has trouble folding compactly enough to allow the top metal cover to snap down properly after the canvas top is nestled into the compartment. This problem was cured by buying two canvas belts from an Army/Navy store and fixing them on each side of the compartment with two brackets, each made from two large picture hanger brackets nested together for strength and covered together with shrink tubing. A pair of brackets was mounted on the bottom of each side of the compartment using 8-32 screws and nuts so the each canvas belt would be constrained to the bottom of the compartment but able to move front to back so that when the top was loaded into the compartment each side could be buckled down with the belts. With the belts being able to move, the buckles can be shifted so as not to harm anything or be in the way.
Finally, to be sure that when you want to raise the soft top, it can be picked up as one unit completely to a vertical position, I always have a canvas belt without the buckle laying in each side of the compartment, with the ends front to back, when I lower the top into the compartment. That way when you want to lift the top you can grab both ends of the belt and pull up the entire top all at one time. Again, it helps if there is another person on the other side doing the same thing with the other belt. You all know what happens if you don't pull up the ENTIRE top out of the compartment at one time!
Another hint - to prevent the rear vinyl window from creasing. While you are at Lowes buy one length of foam rubber pipe insulation like is used to insulate air conditioning lines to your home HVAC unit. Get one that is about 2 or 3 inches in outside diameter. Go to a sock store and buy a pair of childrens long knee-length fuzzy winter socks. Cut off about 3 feet of the pipe insulation and thread one sock over each end so that they overlap in the middle. As you lower the top into the compartment put the sock covered insulation thingie into the fold of the rear window as it goes down. As a final note - I have found the Maguire's vinyl care kit to be superb in bringing back to life an older vinyl window.
Apologize for being so long-winded. Have a happy holiday!
Les 1970 280SL