Spring Update!
It is really starting to take off - very pleased with the results so far.
Wishing I had used a different color of wire, and perhaps done more work on the branches, but overall it seems to be filling-in quite nicely.
The akadama and muck mix worked out well for the BC.
The sun moss is regenerating regularly, although a squirrel magnet for whatever reason. The fertilizer cages are a good way to focus / saturate nutrients into the akadama areas, and keep fertilizer from killing too much moss.
I took
@William N. Valavanis and
@Silentrunning advice on the outer trees (I tried to during potting but couldn't get the right "lean" at the time), and leaned them outwards more. I used so short bamboo wedges to push them out against the other trees, and they seem to have set.
Thanks all again for the great advice on this one! Will be interesting to work on it again.