RE: "If solar particles are generally only 10 percent; does that include GCR? "

Not if you mean cosmic rays by GCR,

Re: "And if it includes GCR then why is there so much solar radiation? [Solar particles are blocked by the Earth's Magnetosphere (as are the GCR) the remaining solar radiation isn't significantly blocked. "

This is a common misconception. The magnetosphere only blocks some radiation particularly solar radiation. A large portion of cosmic rays punch through the magnetosphere due to their high energy. Our atmosphere is a major source of protection by providing a physical barrier just as it does for small impactors.

RE: "Mars distance should significantly reduce this "remaining solar radiation, but because of the lack of a magnetosphere, Mars would receive more solar particles (and GCR). Also Mars' distance from the Sun reduces the the reduction in GCR from the Sun magnetosphere thereby increaseing GCR at Mars distance in comparison to Earth distance.]"

The heliopause is beyond Pluto's orbit. I don't think GCR varies that much within the solar system. The strength of solar radiation and energetic particle density is inversely proportional to distance squared so the incoming solar radiation is less than half the strength at Mars than it would be at Earth. This is mitigated in Earth orbit by the protection of the Earth's magnetosphere and almost totally eliminated at the surface by our atmosphere.

RE: I wonder if this difference is due mostly to how big Earth is from ISS in comparison to how big Mars is to Odyssey? And if so then the difference is largely to due to the blocking affect of the solid Earth- Earth is much bigger from 200 miles than compared with 100 miles from Mars. Another way of saying this is that the total daytime in orbit around Mars should be longer than total daytime in orbit around Mars. Therefore a useful comparison would be to know the average amount of radiation per hour daytime for both Earth and Mars.

Orbiting a few hundred miles above planets thousands of miles in diameter means nealy half the sky is blocked at all times and 50 percent of your time is in sunlight in both cases. I think the differences in size are a negligible contribution.

More detailed article

Variation of radiation intensity with atmospheric g/cm^2
relate density to height

Composition of cosmic rays

Radiation fluxes

Regards,
Mark