31 runningboards used a molded on the board cover which had a 1/4 round edge which abutted the side trim pieces. Reproduction covers are cut from a roll of pyramid matting. One manufacturer makes the correct 31 boards with moulded covers.
The original running board trim was made of zinc, reproductions are offered in zinc-plated steel or stainless, natural or polished finish.
1930 runningboards were 1 piece with the splash apron. The forward section of the aprons were welded to the front fenders.