There is a multi-year gap between the retirement of the Big 4 TPO's and the introduction of their BR Mark 1 equivalent.
Thank you for spotting that. I had not realised that the BR Mk. 1 TPO was introduced later than the other vehicles; I have now put back the retirement dates for the LMS and LNER TPO carriages to match the introduction date for the BR Mk. 1 TPO.
Thanks! However the necessary coupling constraints to enable them to be used with the Mark 1 BG seem to be missing.
Wouldn't it be better to make the Mk. I TPO intro date same as other Mk. I coaches?
I have now committed the fix to the master branch of my repository.
Thank you very much for that: that is most helpful. Now incorporated.