We tried to fixed the stuck margins (we had about two inches of space between the left and right margins) by hitting the Margin Release key and then the Set and Clear keys.
WRONG WRONG WRONG.
All we were actually doing was setting tabs.
The margins were still stuck, the left margin way over in the center of the page.
However, once I knew that I was dealing with a Remington Rand KMC, I was able to find information on adjusting the margins. Sometime in the past, our typewriter had a traumatic event involving its left KMC key. Someone had replaced the missing key with a blank piece of painted wood.
It was a mystery key until I identified that blank wooden key as the left KMC key – the key that controls the left margin.
By holding down the left KMC key and the carriage release lever, I was able to move beyond the left margin and set the left margin where I wanted it. Same thing on the right using the right KMC key – and ta-da: useful margins!