A little more progress on the TPO last night, with the yellow lines added for one side of each coach.  These were very old transfers (looking at the Fox logos on the packet I would say pre 2000 for certain), so I was a little concerned as to how well they would work.  While they were a little too brittle to wrap around the ends of the coach, they stuck well and there is minimal film showing (unlikle the ModelMasters transfers for the ER / Travelling Post Office branding which I cant remove without loosing part of the transfer.)   On these I have been carefully using a scalple to cut away the excess film.

There are still a couple more transfers needed, the numbers, TOPs code and owners flash.  I have a sheet of numbers, but it includes NSX/NTX rather than NSA/NTA codes.  However I have spotted Fox do a sheet https://fox-transfers.co.uk/res-brandings-for-postal-vehicles which also includes the small RES logos that I need for a couple of coaches.  The forth will need an EWS logo, which is a little more tricky.  I think an N gauge loco 3 beasties will do the job.  
 

I still can’t find the roof for the NTA,  I thought it lost behind the desk but no such luck.   For the moment I will borrow a roof from another mk1....

At some point I will get on with finishing the other side...