rusty frame crossmember

[Seventy468]

Working on a 72 chevy long bed 4x4 truck and in the process of fixing this gem (shown). I recall seeing a thread a while back about someone replacing these guys, but cant find it now... if you have any input on that it would be greatly appreciated. The frame on this truck its in great shape, from the back of the cab forward... but from back of the cab backwards it all looks similar to this. Not sure why, and it's not a huge deal as we're going to sandblast and paint, however we are going to replace this piece. We just so happen to have a 79 3/4 frame at our disposal and noticed the crossmembers are almost the same (the 72 frame is on a downward slant at this crossmember, as the 79 is parallel to the ground) so it will take some work, but that we are not afraid of. Before we got to cutting/grinding/welding, I wanted to first check and see if there was something easier out there? Is anyone remanufacturing/selling these crossmembers? Again, if not, no big deal, just wanted to pick some brains before sending a frame under the knife.

Thanks in advance.