Can you ID my Maple?

Hi folks i have a tree that i think is an Amur maple but i am not 100% sure.

Any help would be greatly appreciated.

https://www.dropbox.com/s/p0bx09al9jmlu35/20150821_173741.jpg?dl=0

https://www.dropbox.com/s/vhq3t7aqn2l5jdj/20150821_174300.jpg?dl=0

https://www.dropbox.com/s/x1i9dtfiv3od9md/20150821_173911.jpg?dl=0

https://www.dropbox.com/s/tuqoxro5urb1c29/20150821_174340.jpg?dl=0

https://www.dropbox.com/s/ylear6tf62qri52/20150821_174333.jpg?dl=0

Jamie

Hello Jamie - based on a quick perusal of Gelderen and Gelderan, "Maples for the Garden", I think you are right.  This looks like Acer tataricum subsp. ginnala, Amur maple.  There are multiple named cultivars but to me this looks typical.  There are many very good examples of Amur maple as bonsai.

Thanks David, when would be the best time for me to trim it back nearer the trunk. I have read varied times, some say late winter or spring. But I read somewhere that a hard prune now would be ok. I also have a hornbeam that needs taking back too and was wondering if anyone knew the best time (I know it can vary due to different climate)

Hello Jamie - as you say the best pruning time for different species cultivated as bonsai can vary considerably by climate.  Here in northern California we have cool and dry summers with warm and wet winters.  A late summer pruning on maples often works well because new fall growth is not likely to be damaged by an early cold snap.  Bit, I think it best that you consult with bonsai artisans near you for their advice before proceeding.  We have many who post from Great Britain.  

David B.