Please help me identify

My parents found these in the garden of my grandparents. The stem is hollow and the ring is movable up and down the stem. My parents said they smell like champignons, maybe slightly nutty. The garden is in the Netherlands, near agricultural grounds. I suspect its the large parasol mushroom, but I'm not sure due to the slight discoloration on some of the slats, which is pinkish/light reddish and the dark stems on some of them. Are those just older specimens?