I checked out the model for this machine, and found its:
Singer 15-30 (old style 15 class) which go back to years 1895 to 1933.
And as the serial number on the machine is: F527619
So I found out it was manufactured in between the years: 1910 & 1920.
Here are great site for Vintage Singer Sewing Machines:
http://www.ismacs.net/home.html
http://sewing.about.com/library/weekly/aa012400a.htm
The decal is called: Tiffany or Gingerbread decal, check this:
http://www.treadleon.net/oldtreadleo...ls/decals.html
I am trying to find out a place to buy such decal from.