Spreads are roughly similar with flexibility capable of adjustment. Both sets wider at rest unmounted( 6'', 34.5"). Pads on my rail are 3 hole, 3" in Dia.
Also available, Lazarette hatch 35" long 13 3/8" left depth and 15 3/4" Right depth and front edge is 3" high. Anti skid scored on top. half hinges and hasp eye. Good shape.