  Einstein's goal of producing an advanced gravitational model that was
independent of special relativity's "non-gravitational" derivations has
arguably still not been achieved. The author produced a paper in 1998 outlining
a possible method of attack on the problem based on shift equivalence
principles ("Doppler mass shift"). Some problems with this paper have since
come to light. We list some further developments, some papers not cited in
gr-qc/9807084, some experimental results missed by the author, and identify a
problem with the paper's approach to aberration effects.
