I have lived through too many badly laid out portable keyboards to attempt to build or use anything as pictured above.
In typewriters “condensed” is a term for reduced keys, used on some portables. The term is also used in fontography, leading to a difficulty in searching for reduced keys being called “condensed”.
As it was, the exclamation mark (apostrophe backspace period) and number 1 (lowercase L) being omitted became a standard for a time.
I once saw, and should have bought, a working “ultra condensed” that had just 3 rows of keys, but a shift key with 3 steps. Caps, lowercase, numbers and symbols. I am quite sure it was a Corona and labeled “Ultra condensed portable”. For all of the Web’s depth, I can’t find a picture or reference to it. A Corona Condensed is the best I could find on eBay.
At least it has a period and ampersand.
Being dyslexic and dysgraphic I use a typewriter regularly, and for quick labels, forms, and notes to my family. I like the reduced form factor, partly because of how I learned to type. My parents somehow found a typing class when I was a kid and they had actual ancient manual typewriters. I still remember the smell of typewriter oil and ink, the feel of the keys abruptly hitting bottom as character struck the paper- sometimes removing a bit of paper. It was a little like a Twilight Zone episode, the room, even the teacher was desaturated and gray. At first all that were used were the letters, for days on end. When the class started to get in sync with her call-outs, she added new twists. I still remember the flesh between my fingers hurting, as my child’s fingers stretched and disappeared into the machine. (The image of my fingers disappearing is purely a mental fabrication, as the keys and my hands were covered by heavy card stock taped to the typewriter.) - I digress.
I find the idea of a reduced keyboard interesting, and as it is, I have my computer set up to expand scruple (℈) and ellipsis (…), as well as some of the vulgars (fractions) when coded as I type. To have my devices convert and all punctuation as I typed, that would be pedantic and terrible to live through. At least it isn’t typing text on an old dumb phone, or being stuck with only a virtual keyboard platen and be forced to use a mouse to enter text. My stereo had two buttons for entering text (next char and enter)- that was painful.