Apparently, many people have grafted all kinds of apples onto native Oregon crabapple. A guy from Bullock's permaculture wrote,

"We often use Malus fusca (our native crab apple) as a rootstock for our apples. When we find a native crab apple growing in the blackberries we clear around it and graft a yummy domestic apple onto it. This results in a situation where we get apple production without doing any of the establishment work or nursery care. If the rootstock is already there and established we are definitely proponents of taking advantage of it."

Another guy on the web does this too.
:"To date, I have successfully grafted numerous cultivars of domestic apple (Malus domestica) to the Pacific crabapple (Malus fusca), a wild species native to the Northwest Coast of North America. Malus fusca is a small tree that is very tolerant of poor drainage and salt spray. It often comes up in thickets of salmonberry (Rubus spectabilis), which is thorny and thus protects the young crabapple trees from deer browse. The crabapples, while edible, are relatively small and in contrast to many apples of cultivated origin, need to be dried or pickled to be enjoyed.
Malus fusca makes a useful rootstock, however, for those wishing to grow apples in wet, maritime climates. Malus fusca appears to show resistance to common diseases and the small size of the trees makes harvesting easy. I find its tendency to send up suckers useful as it provides a continuous supply of new places to graft onto. I have 'top worked' several older trees, using a technique called 'crown grafting' (which is a little brutal), and also by wedge grafting scions of many varieties to the ends of existing branches. These 'repurposed' trees now provide bushels of fruit on a site that used to be unsuitable for a conventional orchard because the soil stays waterlogged all winter."

The second guy is in BC, and I think it interesting to think of it as not only useful for poorly draining areas, but also to fight against diseases.

I believe that I am going to try some of this very soon. I have some guerrilla gardening/grafting sites that I want to try.
John S
PDX OR