Found by Ian Suddaby at Larkhall, Lanarkshire.
Find location would suggest Scottish origins but…..
The brick was found in the river so it is water worn but it is still obvious that the frog is a rather unusual shape.
If the brick is of Scottish manufacture then the following are possibilities with regards the brickmark……
Tannochside Colliery in Uddingston (TU) which was owned by Calderbank (C) Steel & Coal Company in 1896.
There was also a group of Scottish collieries called United Collieries. Was the Tannochochside Colliery part of this union.