You may have caught a few of the discussions where many of the experts have said it is not usually possible to give an ID for Japanese maples.
One of the problems is that there's many thousands of registered Jm cultivars and many look superficially similar so accurate Id from a few pics is only possible for a few of the varieties that are very different from any other cultivar.
There's also the question of seedlings. Each and every seedling is a new genetic individual so cannot be given an existing name, even if it looks similar to an existing cultivar. Cultivars can only be reproduced asexually (graft, cutting, layer, tissue culture, etc). I can't see any obvious graft site on your trunk (grafting is the most common method of asexual propagation for JM). It could be cutting grown or layered but more likely seed grown.
I guess that's a long way of saying it's not possible to ID your maple except that it is definitely a Japanese maple and a very nice one at that.