Yes, that is 80s TTB, weled togther with a bar to form a solid axle, and stuck in a 79. Someone posted it on a facebook group and asked if it was a good idea (after he did it already)...
That looks like a hack job to me,with a TTB front axle from an 80 up truck or Bronco with coil springs, if y was going to do that swap I would have gotten all of the associated parts and pieces to do the swap correctly. So that it would have. Been done right and been safe.
I have seen the ttb axle made a solid and put back into an 80's truck, and they were meticulous about it, bit never have seen nor would advise anyone to add the tube and mount only from it... I can imagine the carnage and maybe lawsuit when the welds break loose from the tube from too much stress...