Hi, looks good , did you at all look at the Genesis bogies ? , I am working on an old kitmaster power unit having painted it now in reverse blue grey, it has a correct trailing bogie, and adding Hornby type jumper cables on the front from a class 50 pack. I might look at your Lima route it makes good sense vs the existing triang type option.
I have also flush glazed a triang unit and coaches a very easy transformation, but mulling over the catering vechicle with a sticker overlay off eBay where the grey is a bit darker and a need a find a further carriage to rearrange the windows.