I just mounted new standard OFF THE SHELF 2 point lap belts in my 1951 3100. It was a breaze. I bought 2 pair (left and right from Advanced Auto Parts (black in color) 60" length (max), the belt kits are about $15.00 each and come with all the neccessary mounting hardware, belts, L brackets, bolts, dimpled flat washers, and nuts. It only requires determining proper location, a drill/bits and wrenches to install them. Location of the belts was determine sitting on the bench seat centered in front of the steering wheel and placing small pieces of masking tape on the seat BACK, where the seat back and seat cushion meet an inch or so on either side of my hips. Remove the seat cushion bottom, and use the tape locations to establish approxamately where the belts should extend to the floor pan. Slide the seat frame all the way to the rear position, mark a straight line on the floor pan in line with each tape mark on the rear seat back and locate a drill point about 2-3 inches forward of the rear seat frame. Carefully drill a small pilot hole ensuring that the drill does not hit any frame or mechanisms UNDER the floor pan. If all is clear underneath, drill a hole the diameter of the seat belt bolts and install the mounting brackets with the hardware provided in the kit as per instructions preferably with the L bracket vertical portion towards the rear. Repeat this procedure for the passenger side, or duplicate the position of the holes using a tape measure. Some adjustment of the overall length of the straps can be made at the L bracket when you loop the belt material through the bracket (as per the instruction pamphlet)to achieve your optimum length and look. I mounted mine with both push button release straps towards the center of the seat, with the flange end to the outer. The install was simple, and took about an hour. Other colors of these belts are available at most parts stores.
