The are about 3000 apart 779,xxx (smooth pushers) left and 775,xxx right.
I
also have some theories about the inside dial right side. There are
some gray like theses and some more black. From my observations all
(most) of the black subdial variation have 8xx,xxx i.e. (84x,xxx) higher
than the 7xx,xxx. So for me it seems the gray was earlier that the
black which is contrary to some other's observation but I did not see
them reference serial numbers in their theory.
Any thoughts for your observations.
Bill