I agree your tree appears to be Acer palmatum.
The seeds/keys of Acers are called samara.
For each sp there are distinguishing features... speed of growth, shape /size of leaf, bark and the samara. Different Acer sp the angle of the seed pods/samara is different.Not easy for anyone except Acer expert.
eg.This is Acer circinatum
Below is Acer Griseum.
Below is Acer pseudoplatanus
In UK Acer palmatum seeds grow easily...each seed will produce a tree that may be slightly different from the parent. (Think of humans... Female plus male ..... the children will all be slightly different from mother and father and different from the siblings)
Young plants Of Acer palmatum are used as rootstock for the very many special named Acer palmatum dissectum.Only by grafting can you guarantee a named special...a clone...an identical tree
To cross pollinate plants involves taking pollen from the male flower of one tree to the female flower of another.
Then protecting that flower so no other pollen falls on to it.
Not at all sure why you would want to bother to do this.
Far quicker to grow from seed that you have.