The scratched finish is common...please don't let it bother you...she's still a pretty baby!! :)
To get a more accurate idea of her actual birthdate (no one knows exactly what days particular machines were made), look up the next run of 99s...figure out where your machine's serial number falls within IT'S OWN RUN, and you'll have a better estimate of the month it was actually "born" in! :) Example: My 15-91 was commissioned November 9 of 1945, the next run of 15s was April of 1946... "Anne's" serial number is in about the top 1/3 of that run of numbers...I figure she was actually made in January/February of 1946.
Whatcha gonna name her?