it is good you checked, it means you really care and love this hobby, i have high respect for people like you for doing that.
Looking at the beam i would ascertain it being of what we now call black iron, very high carbon steel, the new alloy steel will not weld very good to the beam and the welding wires would not work very well. There are Arch welding rods (forget the type #) for black steel, think gas pipe for under the road.
i would think of bolting the beam to a tool bar such as you made for the box grader and a range of shovels could be attached such as middle buster, sweeps, chisel tooth, and so on.
Edited by trowel, March 21, 2014 - 08:02 PM.