I just read pages 3 & 4 of the "sailguide" pdf and went out and checked the boats again and discover that the little adjustment screw in the top of the upper casting of my newer 16 is there to help firm up things once adjustments are made, not to adjust rake in any way. And that indeed to adjust rake, if needed, I will have to follow the new hole(s) in the rudders process. I also see that one of the tiller tubes is slightly bent(in a horizontal fashion) which will prevent good rudder alignment. The tiller tubes on both of my elderly Hobies have slight vertical bends, but the catalog only shows straight black tubes. Will straight tubes work on my boats? Thanks again, ripRather than add another reply to myself I will edit this post by an addition to the info I have discovered. Comparing my 83 to the 80 again I think I know what happened to the 80. Somebody reversed the upper rudder castings on the 80! Anyway that's what it looks like and I am going to reverse them back so that I can get the rudders parallel with the adjustments on the end of the tiller crossbar. Phew!