Check a published serial number list to find the date of manufacture for your Singer sewing machine.
Serial numbers on Singer sewing machines manufactured prior to 1900 are numbers only.
Still in existence as of 2010, the Singer Sewing Machine Company itself is a useful resource for information about your machines.
Look for the Singer name on the front of your machine to confirm its identity as a Singer sewing machine.
For demonstration purposes in this Instructable I will use a vintage machine probably dating from the 1950's or 60's because it's easier to show the mechanism, however, all machines work in the same way.
If you can get hold of such a machine, so long as it's complete, you should be able to keep it running indefinitely and certainly much longer than a modern machine.
Whether it is a brand new or vintage machine, the Singer brand name will be on the machine.