12 was the only one with black despite Lima's 25 ! Whatever was on Cardiff from the Portsmouths would have appeared on the Crewe workings so yes it most likely did turn up along with the white examples. Despit being brought with 33s and mk1s, I have never seen a FULL list of locos that carried white. Anybody have one.......????
Midland Outpost - Memories Of Barrow Road Shed by D J Fleming. RP Publishing of Bristol. No ISBN number 1984/5.
Also, The Best Way To Bath by Neil Burgess with the same publisher 1984. Of note too is Memories by Anthony Wray with Avon Valley Publishing 1988. These are all paperback but i should think now difficult to find. The Avon Valley Railway may be able to help. Their own Semiphore booklets may also shed light.
I have a photo from a local book that shows one going south through Warmley. They were quite regular at Barrow Road as they would often run light from Westerleigh for crew changes. Again, sourced from a local book written by a former driver.