Without seeing your toe rails it is difficult to know exactly what will
work for you in regards to securing covers over them.
I made my toe rail covers using the same design as we used at The Ship's Tailor in Deltaville when I worked there. I placed pencil zincs (which can be purchased at most
fishing shops) inside the facing every 12 inches along the
deck side of the cover then used leech line ties at each stanchion. On the
hull side of the covers I needed it to extend over the
teak rubstrake, so was able to use snaps on the underside of the rubstrake to secure it. If you don't need the extra length, then pencil zincs
work well on the outside. When we lived on the Chesapeake, I used small Sunbrella bags loaded with sand (inside a sandwich bag) that clipped onto grommets placed along the hem.
Hope this helps. Cheers, Katherine