Thank you everyone for your contributions & my research is ongoing, thanks to your pointers I have come up with the following candidates & I am looking for more......
25032 dual braked in 1974, allocated to Cardiff in May 1974
25048 dual braked in 1975, allocated to Laira 1978
25057 dual braked in 1974, allocated to Laira 1978
25058 dual braked in 1974, allocated to Laira 1978
25032 probably is my favorite at the moment as it would run alongside my Hydraulics circa 74 to 77