You can tell when a kit has been designed by someone who actually builds them. There are little touches that others wouldn't bother with. In this case, designing the model so it is modular for easier painting should the builder fancy a complex livery.
The cab has a separate floor around which the sides are assembled. First the doors have to be fitted in the half etch recesses in the side. You could use superglue but I soldered as you can't solder the handrails in place if you've used glue - the fumes given off contain cyanide ! Next the rivets are punched in the side. I've used 4mm versions as in this case slightly too big trumps far too small.
The front and back (make sure you get them the right way round) are fitted and then the sides go in. The later overlap the former.
Finally, handrails. A sliver of Formica was used to ensure they are all the same distance from the side. Clamping the 0.45mm wire between this and an old lolly stick allowed me to wield the soldering iron inside and get a good gob of solder to grip them securely.