Phil_F_NM wrote:

That's a Smith-Corona Silent (Silent as seen on the plate behind the paper tray). The serial number should be under the ribbon cover, engraved on the left side of the chassis. It is the same model and finish as my first mechanical typewriter, and one of the best machines I've ever typed on. The platen is easily removable and the mechanism is great to work on, since it does not have the tabulator built into the keyboard. Tabs are set using actual metal tabs that fit into corresponding grooves in a tabulator rack behind the carriage. 
Clean the case up with some mild soap and water, watch out for solvents, as they will soften the crinkle finish. Be careful if you're taking the brown crinkle paint panels off, as the screws can cause the paint to buckle and chip, leaving a nice bright spot. That whole machine should be really cleaned very well, lubed up in the right spots, and used for writing. Those can handle a beating and can be made to be very smooth and almost effortless typers. My SC Silent spoiled me to the point that I can't type on any Olivetti or Antares now, they just feel mushy. Another great thing about the 5 series SCs (your Silent is a 5S) is that the escapement is very easy to work on and fine tune, if needed. Clean it up and it will probably outlast you, as long as it's taken care of properly.
Phil Forrest

Thank you so much! You are awesome!!!