Here is what is fun.
000,001 Singer started using 1/1/1910
to 999,999 and then they went to 1,000,000 in Jan 1911
they used numbers up to 9,999,999 and ran out May of 1923
and to get more, the went to
0,000,001 which is NOT the same as the starting 000,001
and they went up to 0,999,999 to Aug 1924
Because the next number would have been 1,000,000, but that was already used way back in 1911
So if you have G number - really pay attention to the exact number of digits - because they have both 6 and 7 digit numbers.