ok, maybe I am too zealous
The truth as I see it is that the Jew had fallen into acceptance that it was the present sacrificial system that produced the reconciliation of the Messiah.
Perhaps it is difficult because you are attempting to tie your belief system to a particular scripture and for this reason are only seeing the tree instead of the forest. (this would be acceptable if you were a logger

). On the other hand, perhaps I am viewing so much of the forest I am unable to see the 'tree.' However, in order to recognize the individual truths that are taught in Scripture it is true that we must place them in light of the rest of the revealed text, correct?
OK, then it follows, in my way of thinking that the O.T. sacrificial system is relevant here because the apostle is speaking concerning the Jews; and this ties Rom. 11 to the entire Jewish system of sacrifices and worship of the Temple etc.
Because of this view, which I admit may only be my own, it is impossible for me to approach such scripture as at Rom 11 apart from drawing on the limited knowledge I possess of the O.T. system.
I am sorry for any confusion this system creates among all the readers here, but this is the approach I take, I have yet been unable to break from it.
God Bless.
Bro. Dallas