I went back to the nursery that gave me the 'Indian Breadfruit" and learned two things. First, Indian Breadfruit is nothing more than Jackfruit. Apparently Jackfruit came to Fiji from India when the British brought Indian labourers to Fiji to work sugar cane plantations. It is more commonly called Jackfruit here, but apparently some of the indigenous people still call it Indian Breadfruit.
The second thing I learned is that I was given the wrong seedling. My earlier photos of the mystery plant were really only an Ivi nut tree. I already have Jackfruit in the ground, so didn't bother getting another.
Here's the real "Indian Breadfruit" (Jackfruit) seedling:
And the mature tree from a nearby yard: