[cletrac (RIP)]

I've been asked for more details to reproduce the top bows so here goes.
-the bottom channels aren't channel iron but have been bent to shape. The corners of the channel are rounded. The channels and the welded on plates are 1/8" material.
-the channels are 57 1/4" long then the ends are welded on giving a total length of 57 1/2"
-the end vertical pipes are tight against the channel and the end piece.
-the centre vertical pipe is tight against the channel.
-the holes through the channels by the vertical pipes are 3/8". These are for the bolts that hold the bow assembly onto the box.
-the centre holes are in the centre of the 2" wide horizontal plate in line with the vertical pipes and are 3/4" in from the side of the channel.
-the end holes are 1 1/4" from the end of the channel and 3/4" in from the side of the channel.
-the footman loops are 2 3/4" between centres of the bolts. The footman loops are riveted in place. The inside rivet holes are 12 3/4" apart and centred on the centre vertical pipe.
-those little holes along the sides of the channel are threaded for 1/4" NC bolts. One is centred on the middle vertical pipe and the rest are spaced every 7"