I went to my local carpet store, and took the measurements of my ironing board, they sold me wool carpet underlay which is the same as the wool board I purchased from my local quilt shop. I found the wool board too small as I generally make larger quilts, hence purchasing the same from the carpet store. They even cut it to my ironing board dimensions. Dimensions of my rectangular board is 24 inches x 60 inches, which I had made to fit on my regular ironing board. Yes it presses the seams so much better than just using the ironing board without the wool board.
There is no smell if you spray your wool mat with lavender essential oil, I made a solution of 2 cups distilled water, 20 drops of lavender essential oil and 2 ounces of vodka - the vodka keeps the water and oil from separating. I keep the spray in my sewing room, and use it for all my ironing and pressing. It also keeps our closets smelling lovely.