1984 measurement   (m_n-m_p)/m_e = 2.530947935 +/- 3.1e-5;  Aspden 2.5309419: -2.38 ppm, -0.193 sigma
CODATA 2022        (m_n-m_p)/m_e = 2.530988574 +/- 7.4e-7;  Aspden 2.5309419: -18.4 ppm, -63.1 sigma
In MeV with today's electron mass: Aspden 1.29330866 MeV vs measured 1.29333251 MeV
His printed 1.2933214 MeV used the 1984 m_e; against today's 1.29333251 MeV that mixes units and gives -8.59 ppm
