I finally got it by adjusting the side nuts slowly and in order from front to back.  Each nut made a subtle change.  They must have been changing the slant of the carriage.  

I have come across an Olivitte Underwood in an antique shop.   As I have three others I am familiar with them, sort of. One is an Olivitte studio 45 inclosed in a beautifully designed casing, turquoise.  Another two toned brown and cream.   The casings are plastic but stylish.   The last is smaller in a metal casing, something 22.  Then all type with a light touch that I love.   But the one in the antique store is different, looks late '50s and more heavily made. The controls are 'heavy metal, no plastic, chrome,  and the carriage runs on rails that are different--not visible from the top.   It has a more solid feel.   The question is, was that Olivitte's top design for professional use?   The price is $65; is it worth it, or could it be found cheaper?   It comes in a cream colored carrying case , stylish.

Did check the touch control but it does not affect the position of the platen.  But...there is a nut in the back of the carriage that does.   It us on the right side, looking forward from the back.  A screw holds it tight, then when turning it, it adjust the platen.

The line space regulator spring fell out of the Underwood Noiseless 77 when I removed the cover plate on the left side of the carriage.   Looks simple enough, but I cannot find how to put it back in: any tips?

I'm sorry, the Remington is a Quiet-Riter.