I have had difficulties grafting these two. They look great, they're doing well, and then slowly they seem to die from some disease. Has anyone on this list had experience grafting these?

I wonder if summer budding would be more effective?
Thanks
John S
PDX OR

Certainly worth a try, John. I have both grafted, they did not seem at all unusual in their behavior, but they are also not on standard rootstocks. One is grafted to perhaps a granny smith trunk and the other is grafted to a random seedling, FWIW.

I suspect there are clonal rootstocks that have difficult times with certain crabs.