I borrowed your idea and grabbed some seeds and cuttings from a Japanese Maple Tree at my parents' house and I am propagating them to distribute to siblings and kids. Below are some starter branches. I read that you need to start in moist soil and spray frequently. Also, below are seeds I collected from the ground which are red and seeds from the branches which are green. The red ones should work best. The seeds are strictly a backup in case the tree propagation fails. I also read that the branch starter will yield a genetically identical tree while the seeds will have genetic variations. Thank you for a great idea @papa-pepper (if you are interested in any Japanese Maple Tree seeds please let me know and I will send them...).