The following is a paper by H. Aspden published in Speculations in Science and Technology, v. 8, pp. 235-239 (1985).
Abstract: A neutral aggregation of Thomson-sized charges is shown to have alternative forms with the same energy. Taking the proton and electron as constituent charges in a four-charge system, it is found that the other charges have an energy approximately 273 times that of the electron. The system is then shown to be conducive to a remarkable wave resonance condition, yielding a free pion state with a mass of 273.127 electron units, exactly in accord with the measured value.
Commentary: This paper is one that is truly remarkable. Although the author had been delighted with the discovery of the pion creation process reported in his 1980 book 'Physics Unified', the new contribution made by the subject paper added enormously to that satisfaction. The reader will not appreciate this without working through the paper. Nature, it seems, is always trying to create particles and the ones we see are the ones which win through in the contest for survival. Although the electron and the proton are the ultimate winners because they are the first derivative form from which other particles build their existence, there are a number of unstable particles that survive long enough to tell us how the creation system works. Whereas the virtual muon and the tau lepton are natural denizens of the aether, the pion is a spin-off creation from the general particle energy activity. The pion is the particle which seems to have dual chance of existing in an energy exchange mode involving a core particle that could be a nucleon. In fact, as the subject paper shows, the two actions may contribute to determining, not only the mass of the pion, but also that of a nucleon unit of mass that is 1833 times that of the electron. Much depends on whether the pion really exists as a stable particle as part of the chain-structured binding energy of an atomic nucleus, as discussed in chapter 7 of the author's 1969 'Physics without Einstein'.