Wow that fruit looks good. I would plant the seeds you got from that fruit and later on you can graft onto the
seedlings? Hopefully you will get a bunch of seedlings and can try grafting in the spring when you trim your trees
anyway? I have raised Na Dai sugar apples from seed and I got flowers after 2 years and fruit at 3 years? I don't know
how fast A. reticulata grows but I assumed the same fast growth? I currently have 2 seedlings from a sugarapple X custard
apple cross that produces large fruit. I hope I have fruit in 2-4 years. Mostly I have seen cleft graft used to graft Annonas
which is very easy to try. I only have one roll of grafting tape now. Can you order online and have it shipped to you?
https://www.amazon.com/Parafilm®-Grafting-Tape-Genuine-Clear/dp/B0085OFNZK/ref=sr_1_12?ie=UTF8&qid=1517031229&sr=8-12&keywords=graft+tape
ebay and amazon have hundreds of shippers. Let me know if you need help getting it to you.
How many seeds did you get?