As mine is 23798, this would mean that she is was produced around 16-18 February 71.
And the one with the highest number (Chris's) evidenced in the Forum Car Registry - 2 days later...
BTW, if we want to track down those things so precisely, we would have to establish whether there were 20 working ays in February 1971 or more... Back in those years in many countries Saturday was a working day, and besides - who knows - maybe Mercedes had a continuous week work rules?