Grade up Combres?

For the last two years I have had the good fortune to operate a speeder with M. O. W.
I have ridden the train several times but didn't realize how much the grade varies on the west side of Cumbres until actually at the controls. Some two or three miles out of Chama around MP. 341 the grade picks up sharply, then eases off at Lobato. In an earlier post, Earl said at the west end of Lobato trestle the grade is actually level.
The grade picks up shortly after leaving the trestle but is not a constant grade to near
Coxo where it eases up for a ways then is quite steep around Windy Point. My question is, what is the maximum grade and where is it located? Was it always this varied or have sags developed over the years.
Thanks in advance
Jim