I have what most likely is a strange question. But here goes!!!
I have  pictures of my father with a 38 Oliver 70 which in some pictures
has the motor curtain on and in other pictures with them off.
I know that Massey-Harris had them on their 101's 102' and maybe
a few other models.  Oliver did not use them for many years.
Did they cause the motor to run warmer as to not having them?
Other than make the tractor in some cases look good what was
the purpose of them.  Thanks for answer.
Jimmie