Hi: Disrict 17 is Hopewell and West Branch East River.
A few MacLEans's there including our ancestor Hector MacLean 1772-1854. In my printed version of the 1851 census I have noted that your Donald is Probably Hectors son Donald. But I have our Donald married to Jessie McKay (1817-1893) and different children than you have. I see three Donald McLEans in Dist. 17.
Donald isn't my direct line so haven't done much with him but I do have a list of children and birth years.
Drop me an email and I'll send what I have.Bill_Dunbar@msn.com
REgards- Bill in Montana