Trying to locate some Malay Apples, in Hawaii we called them Mountain Apples.

Have you tried Uwajimaya Supermarket ? There is one in Seattle and one in Bellevue. I go there for my specialty fruits and vegetables. Grew up in Hawaii- it's the closest you'll come! Got some beautiful passionfruit, long beans, bitter fruit and taro root there last week. The Seattle one is much bigger than the Bellevue store. Well worth the trip!