I acquired a VG condition Olivetti that required minimal cleaning and appears to work in all aspects but was initially thinking the tab control was not operable.  I am more familiar a with SMC Classic 12 so I was stumped as to why when I set the tab that after pressing Red tab key that that the carriage never moved.  It took me over 30 minutes of playing with this that I discovered it will work if I simultaneously press Red tab key and the carriage release lever...in other words it is a two finger operation instead of one finger Red tab press.  Is this normal?  The skimpy manual, really a   printed card, two sided, does not help.  I realize that some typewriters don't have tab functions at all and I myself will use it sparingly.   Just curious.