Ok, thanks. The model proposed in this paper has some issues which, AFAIK, were not necessarily understood in 1973 when Tryon published the paper, but which are clear now, decades later (and AFAIK have been discussed in multiple papers during the intervening years):
The model requires our universe to have zero values for all conserved quantities. This would include a zero net particle number (i.e., total number of particles minus total number of antiparticles), since in Tryon's model all matter would have to be created by pair production. But our universe has a slight excess of particles over antiparticles. (This was not known in 1973 but is well accepted now.)
The concept of "gravitational potential energy" Tryon uses is only valid in a stationary spacetime. But the spacetime of our universe is not stationary (it's expanding).
One could in principle formulate an alternate definition of "gravitational potential energy" that would work in an asymptotically flat spacetime even if that spacetime was not stationary (for example, such a spacetime could describe the gravitational collapse of a massive star to a white dwarf, neutron star, or black hole). But the spacetime of our universe is not asymptotically flat either.
Tryon's model is based on a closed universe, but our actual universe does not appear to be closed. (Strictly speaking, a closed universe with an extremely large radius of curvature, much larger than the size of our observable universe, is not absolutely ruled out by our data, but it is highly unlikely.) For this discussion I assume we are ignoring this particular issue since the topic is closed universe models, but it is still worth mentioning.From what I can see Tryon does not mention pseudotensors at all, nor does he give any detailed mathematical models. He only uses a few heuristic equations.