Trying to find a simple lock to fit this but as you know a simple standard one will not work. What do I need or what is it called. does not need to lock only need to shut.
One of any standard type of locks which have a rebate kit, which is a box metal plate that takes up the space of the rebate on the door.
Depending on your lock either of these: http://www.screwfix.com/p/eclipse-m...it-polished-brass-93mm/53903?_requestid=11727 http://www.handleking.co.uk/rebate-kit-for-double-doors-with-brushed-nickel-finish-l2201np