While the structures of matter are many when distilled into their two energy components, they are potential and kinetic.  Ultimately, as hypothesized, the source of potential energy is the spin and the source of kinetic energy is the contained space. Perhaps reviewing Structure # 1 and Structure # 2 will close the loop between magnetism, energy and matter. This goes on to explain the origin of gravity from structure. (See Author's Thoughts)

Matter from Magnetism

While we are correctly taught that a magnet's fields are sourced from that magnet's atomic and molecular structural alignments, we are not told of the energy source or structure of the responsible electrons.

This hypothesis addresses that issue squarely. Not as the differentiated particles of Particle Physics, but as the structures of mass and energy that build the substance of such differentiated particles. The dimensional differences are vast, but the concept of magnetic structures from a magnetic ether is sound.  

If in doubt, look at the fields surrounding a permanent magnet. Different diameters, same velocities, must have different frequencies. Planck's E=hf   Each motionless spin contributing to that magnet's energy and mass.

Mass from Massless Momentum?

This hypothesis finds the source of mass as the 'Space' that  is within each 2 dimensional magnetic field of light speed 'velocity'. The logic finds its origin in the structure of a magnetic ether that hides its mass within each field of its potential energy that is the source of potential energy's conductive transparency. The light speed velocity of magnetism being the 'Time' aspect of Space/Time.

Transference of energy through the ether is a matter of massless modulation. Transference of energy through particle structures is a matter of modulating mass.