To be fair mine is a quick lash up of a 3D design off Thingiverse with some additional detailing and a wooden roof. It's sitting on a little pug 4 wheel chassis, so technically it's closer to a Y6!! I've basically built it as a more robust vehicle than my trams so that I can send it around and clear the clutter off the track prior to running the more expensive to fix stuff...Yup a Y6 unlike your superb J70. However the differences are small but noticeable, sadly I did not look too closely at yours earlier before I made my boob comment. Vive la différence.
paint brick first!!!!!!!!!!!!!!!!!!!!!!!!!!!!than paint roof...............than add roof.....you dont want to f**** up this master piece, if you dont do it my way, we will have a couple of beers and a talk and i walk him home and you can rebuild....e next process will be to give the structure a spray of grey plastic primer but, at the moment I am undecided as to how to proceed further. I cannot decide if I should paint the brickwork first, or add the roof. I am erring towards the roof, as that could also be primed before any painting takes place.