Hi Mike
It looks like the plastic knob on the release lever has rotated as the arrow should be pointing towards the back of the case. Push the release lever directly backwards and the machine should pop up an inch or so, then you can lift it out of the case. The spring tension on this clip can be quite high, so it may take a considerable amount of force to release the lock as compared to the manual 5-series Smith-Coronas. You can try pushing the front edge of the machine down while moving the release lever as this will reduce the spring force working against the latch. Hope this points you in the right direction,
Sky
We humans go through many computers in our lives, but in their lives, typewriters go through many of us.
In that way, they’re like violins, like ancestral swords. So I use mine with honor and treat them with respect.
I try to leave them in better condition than I met them. I am not their first user, nor will I be their last.
Frederic S. Durbin. (Typewriter mania and the modern writer)