do you have return to cylinder?
we took the new to us old 1980 N5 out to our buddies, and it didnt do that great, but neither did the other buddy who helped finish with his 8230 CIH, so I didnt feel too bad.
we had the sieve down tight, concave to zero clearance, cylinder full speed, but didnt play with filler bars or better cylinder bars. It was having a tough time getting the last few kernels out of the head. new cylinder bars and some filler bars would help alot I imagine.
our buddy with a P3 R70 with cyl. return had done some triticale in the past and said that he ran a bunch of return, but was able to get it all out and have a nice bin sample.
Congrats on getting it done, and doing well to boot!