There's not a lot of detail on the 01 but what there is, is a plethora of handrails and door handles. For such a small loco, it does seem over-supplied with these things. A big steam engine doesn't have nearly as many !
All of this detail comes from an Alan Gibson packed of 0.45mm wire. I know some stuff is provided with the kit but I instinctively reach for the supplies in a pot within reach of the workbench. Not that there is anything wrong with the wire that comes with the kit - a stout cardboard box ensures that it gets to the builder nice and straight, unlike some kits where the lengths are stuffed into a container slightly too small and take on an annoying bend. The leftovers go back in the same packet if they are long enough to be useful. Id not its the brass leftovers drawer for them.
Spacing from the body was set using a bit of melamine trim filed down slightly to reduce its thickness. Being thin and heat-proof, it's idea for the job. Placed against the body side followed by the wire and then a bit of lolly stick to protect my fingers from the heat, the 'rail is held securely enough for me to be able to solder from the inside with aplomb. Clever chaps would clamp this lot together and not risk their fingers.
A nice detail is that the bonnet handrails are held on with the correct form of handrail knob. Not for this diesel the standard ball-type version found on steam engines but the prototypical stub of metal with a hole through the side. I suspect that on the real thing it was cheaper to manufacture them this way and they certainly provided less dirt holding nooks and crannies. If you want to buy some yourself (mine came with the kit), try Markits who have made them for a few years.
Finally, I know the bonnet handles are different lengths. I make them long and will crop them back later. Just didn't get around to it before taking the photo.