GOOD LUCK....that's all I have.
You need to cheat and steal at all the areas you can. The cabs need to be level, but you may be able to raise the doors as you go, only a little. Then your piece of first molding needs to be raised 1/8 or 3/16 as you go. You may not notice a 1/4 inch in 8 feet, tack it and see what looks acceptable. Then you need to raise or roll the crown as best you can. Rolling cabinet crown is probably to hard to do, but another 1/8 of an inch will help. Last is to caulk and match the ceiling color. I have even backplaned some of the crown to get it to sit tighter to the ceiling in the low areas. What is even more fun is when the ceiling rolls continually, then you need to float some compound.
Those are my tricks of the trade.
It is what it is, old homes have character, now you know what to tell the folks on the next job.