The experimental measured result is 782,332. 9 eV
The experimental measured result for ( n- p) is 1.293 332 05(48) MeV
the proper Neutron mass excess of ( n-p-e) = 0.7823329 MeV
It really doesn't matter which one (n-p) or ( n-p-e)......
Quantum funk like QED or QCD can't get 2 sig fig accuracy .. let alone 6 sig fig accuracy.
Its lucky that Maxwell wrote down a classical equation for c long ago..
otherwise QED and QCD supercomputers would come up with 3+-0.1 x 10(8) instead of 299,792,458...m/s