Thanks for the comments
@ Marcin- the kit includes circle card formers. I added paper parts to place them rigth and easy the following tasks.
@ Vinalssergio - I like to assemble the models without weathering effects. Well, locomotives were new before getting old and clean before getting dirty. More seriously, weathering is an art that I don’t master
The side compartments (for coal, if I’m not mistaken) have a solid card structure and many rivets!