Here is a picture of our Acer palmatum 'Little Sango'. It's compact, with red multi-stems, dwarf, and has an upright growth habit. The leaves grow in dense clusters and are much smaller than 'Sango Kaku'. Some of the mature leaves are somewhat odd with bent shape lobes. The larger example of this tree on Buchholz website reminds me of the texture and form found in 'Sharp's Pygmy' of similar size. Introduced by the Flora Wonder(tm) Collection of Buchholz Nursery: http://www.buchholznursery.com/plant_page.html?id=26f9f6
Do you happen to know if this a witch's broom or a selected seedling? I haven't noticed any truncated lobes on Buchholz' website, so I assumed it originated as a seedling.
I was wondering the same thing, but I seem to have found the answer. From Mr Buchholz' Flora Wonder blog (http://florawonder.blogspot.com/2012/06/momiji-madness.html):
I remember that it was mentioned in the blog, just didn't get the chance to look. Thanks for posting the link!