Condolences for you father,,and congrats on inheriting one of the greatest speakers made,I too had some concern of moisture on the bottom of the risers,,so I purchased the solid whit PVC outdoor molding,,its basically 3/4 x 1 1/2 of solid PVC,and I just outlined the bottom of the riser,,scuffed the PVC and sprayed them black and a couple of dabs of construction adhesive and now no more worries..