Ooo, tough one here Abbey, isn't it?
He looks quite fresh faced so I'm wondering if this was taken before he went to do any fighting.
You say the photo was taken in Maidstone which suggests that either he lived there or was stationed there before going out to the war front.
Have you considered contacting the Imperial War Museum to ask them if they have a list of soldiers from the relevant regiment? Do they have any photos with names at all? If you haven't contacted the IWM, below is their contact page link:
https://www.iwm.org.uk/form/contact-iwmWhen you have filled in your contact details, choose London for which branch etc.
For what is your enquiry about, I would pick the 'Doing research at IWM' option
Then you can fill in the boxes at the bottom and see what happens from that.
Worth a try.
You don't say what avenues you have already explored but have you tried local family history societies in the Maidstone area? Or maybe tried to get the photo put in local papers?