Thanks! I'll go back to Leeds on 23rd December onboard: 1D05 0803 from Kings Cross to Leeds (Azuma) 1A50 1945 from Leeds to Kings Cross (Intercity 225 which could get swapped out for an Azuma, especially at the last minute)
The first train from Kings Cross is 1D01 at 0555. It arrives into Leeds at 0823. The next Northern service to Bradford Forster Square leaves at 0841 (2P28) which arrives into Bradford Forster Square at 0907 which means I would've missed the 2 daily trains from Bradford Forster Square to Kings Cross which are: 1A07 (departs at 0630) 1A19 (departs at 0843)
Probably not what you might want to know, but this service fulfilled a need I had a few years ago. I was waiting for a Central Line to London and needed to amswer a call of nature. In comes a service, then to Paddington, hopped on, use the facility and hopped off.