After a fruitless afternoon probably visiting all the wrong builders merchants I was unable to find a short length of 'H' section extruded aluminium strip which I need to join two sheets of 10mm ceiling board. i.e. I want each sheet to slot into the 'H' for a join that doesn't show the gap between the boards and give me some support in the vertical alignment between sheets..
Can anybody tell me where I could get such an item?