Gizzy
A gentleman, a scholar, and a railway modeller....

Having compared Tenmille (made in Suffolk just up the road from where I work), I know the 'foot' part of the rail is narrower than LGB. The method used by Neil to join the two makes, was to file down a short section of the foot on LGB to match Tenmille.Without wishing to get Gizzy's hopes up, I have some Hillman-Clamps-for-LGB-Rail in my "spares" box . . . but I plan to use them * unless anyone can supply me with a decent quantity of Hillman-Clamps-for-Tenmille-Rail.
Your idea to join Tenmille to Tenmille is a good one and I'm wondering if they can supply a Hillman type clamp for their own track....
