Was in the "tropical fruit" strip mall on the corner of Magnolia and Bolsa today and saw a few of the fruit shops there had rose apples. A couple had what looked like pygmy rose apples. Not sure if they were a different variety or just grew like that. One of the places had ones that looked small-ish, but not tiny.
Don't recommend buying any unless you're willing to pay for nostalgia. At $10 for a small bag, they were really expensive. I had to pick some up just to relive some childhood memories.
They're chilling in my fridge now. I'll report back when I've given them a try.