The question is how we would elaborate them today and whether after careful empirical assessment we would in our time echo Grossman's accurate prediction in 1927 that they would soon by eviserated (the lectures were published in book form in 1929)
Edward Wolff puts a lot of emphasis on the growth of low OCC industries in accounting for the partial recovery of the profit rate after 1982. But you can see that this is all there already in Grossman. And the question is how effective we expect such mechanisms to be. It's not that capital will run out of options; it's a question of how radical those options will have to be.
So let me emphasize that the translation does not include the last chapter of the book, which examines novel threats to the well being of the working class (tendency to depress wages below value of labor power with intensification of labor process through Taylor and Bordeaux systems) and international peace. That is, the book does not end with a prediction of mechanical collapse. It ends with a prediction of crisis and catastrophe.
As Levins and Lewontin put it, dynamical systems change their shape at critical values of the continuous variables, so called catastrophe points, as when a stick bent by continuously increasing forces breaks.
This is what happens at years 21 and 34 of Grossman's extended Bauer model.