This is a view of the GUARD RAILS.

The guard rails are made from scale dimension basswood.
Balsa might be used but I've found this to be too fragile.
Pine might be used if you have a way of getting it to 
the correct dimensions. Scale hobby basswood is easier.

One method of assembling the structure is to put double sided tape on your work surface. Place the verticle members at thier proper locations and then position the horizontal members and afix with CA.
Notice that there is a left and right side to these assemblies. Also, every other verticle member is doubled. I suppose this was done to provide a replaceable rub rail on the real boat.