Swintec Typewriters

Judging by the ribbon cartridge type and the spec of 20-22 characters per second I expect they're daisywheel printers. Also if you look closely at the clear cased versions you can see the head assembly which has a daisywheel loaded

http://www.swintec.com/clear-typewriters/21-2410cc-michigan....

http://www.swintec.com/15-print-wheels

> What does the "display" provide, one line of type you can correct before printing?

If you have a read of the spec here:

http://www.swintec.com/48-2640-electronic-display-typewriter...

700-character Correction Memory ( within 10 lines)

You can do some basic correction. I used to maintain/repair this kind of thing back in the late 80's early 90's when I worked as a field service engineer. Some more advanced units could store whole documents and do more clever things.