Have you had any luck with either air-layering or cuttings of Beni Hime?
Since you have experience with propagation, look into cuttings and air layering. Maples can be propagated by both methods. In the Propagation Sub Forum Bonsai Nut has put together an excellent explanation of air layering. Ive been doing cuttings the last two summers of many maple cultivars so if you would like some tips and ideas let me know.Thanks to Sorce and AlainK for your comments.
I am just starting out with lots of 'prebonsai' trees. The art form of the bonsai seems like a tough gig BUT I am excited as have been in the nursery/plant propagation industry all my working life (25 years or so).
Lol, to grow trees for Bonsai and not for the landscape trade is an opposite but very addictive already. Never know, I might be brace enough to post a photo.