Thanks.  Mine types wonderfully as well.

It is heavy for an "ultra" portable...weighing 9.8 lbs. without its case weight.

I also added peel & stick felt padding under the ribbon cover, along the insides of the side panels, and along 2/3 of the inside of the bottom panel.

Even added some felt pads for the "stops" of the space-bar.

Took the metallic/clacky/tinny sound of the machine to a nice wooden-sound tone. 

I also have a Triumph Tippa and a Hermes Baby...both are lighter than the SF...but the SF feels like a fully portable machine when I type with it and it my favorite out of the 2 machines.

And my Hermes Baby (with Dutch keyboard) made in 1968...with the different color to the key-tops and the platen knobs  :
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