Found by ‘Rig Rat’ on the Banks of the Firth of Clyde near Erskine, Glasgow. Unknown maker. Find location and stamp may suggest Scottish origins but … I also think this brick may be made by the same makers as the MAC Brand bricks. . .
Found at Drum Farm, Bonnybridge
Find location would suggest Scottish origins but…..
I am not sure if there is space for another letter after the ‘C’.
Below – It is very possible that the brick above is stamped Celtic as is this example which was found on the Firth of Clyde, Glasgow.