doe sit do to seed? im not expert on anything yet really but ive heard for maples i guess grafts or somehting sometimes have seed that have grown to be differnt looking trees
? not sure of it though good chance i might be wrong,
i think the fact that you never pruned it and it looks like a real nice bonsai is pretty cool, the new mallsai.
that also makes you wonder on its age if it is that slow growing...
good luck hopefully u discovered ur own new species.