Scotland's Brick and Tile Manufacturing Industry

Found by Jim in the Sheffield area. This example is not in my possession. I believe this is a Douglas

Found by JC in Fife Triangle symbol followed by an A and 24 I believe this is a Douglas Fireclay Works,

Found Glengarnock It is a partial brick but I think the mark is whole. Could 1938 be the date? DB = Douglas

Found Firth of Clyde, Glasgow Triangle symbol followed by an A I believe this is a Douglas Fireclay Works,