Back in the old days, when computer monitors were green, I worked for a newspaper in Puerto Rico. Everything goes on deadline, and we would smoke in the business department while racing to finish pages. On Christmas, the paste-up people would bring coolers with beer and spirits and slip booze to the copy editors. Sometimes we had so much fun that the paste-up department put text columns in the wrong order. 
 

Thanks to all for the info and kind words. Sky, I have my eyes on it but just ordered two--an Optima Elite and a Mercedes Prima---and may order an Optima M10, at which point I will be tossed into the street by "upper management." So maybe not for now, but definitely for the future: it would be thrilling to use the same typewriter. Uwe, why are the covers missing? That has always baffled me.
 

I found this jewel of a photo among old pictures.  Do any of you know which typewriter it is? It looks like a Remington  without the cover. 

There are two sets of screws under the carriage: one set in the middle and another on the top sides. I loosened and tightened both without results. I will try the nuts on the back next.

I fly-fish, collect bamboo and fiberglass rods and turn of the century fly reels, hunt, shoot trap, collect first editions and vintage photographs, film cameras, records and briar pipes. I'm a writer and only use typewriters. I read and correspond obsessively.