Hi, good for you for looking out for your mom's mat. I have an idea for your ruler's. A friend here had her DH take a wide piece of wood, hers is 6 inches by 12 inches and 1 and 3/4 inch thick. He used a saw or router to cut grooves about a half inch apart along the full lenght of the piece of wood. It was then sanded and varnished. She can stand all her rulers on end in the grooves so they don't disappear under the fabrics on her work table.
The stands are so popular with her pals that he sells them at quilt shows and local market stalls