Thanks for the compliments!
For the GP16 (unpainted model), the wire on top of the nose is Detail Associates' .006" brass wire (Walthers #229-2501). The wire used for the handrails is Creative Model Associates' .008" Phosphor-Bronze wire (Walthers #363-1100), which is a little "stiffer", less "springy" than brass, and what I prefer. Durability wise, it's a wash. In some ways it's better, in some ways it's not.
Some Tips? Practice and patience.
Here are a few shots of an iffy JnJ GP15 shell that I practiced on. I didn't spend too much money on the detail parts, and as it started coming along successfully, I put a little more into it, and still occasionally use it to try things. With the quality of the shell, it's like "polishing a turd", but it did provide some good practice.
Personally, I use tweezers and small smooth-jawed needlenose pliers to bend these items. But try different tools until you find the ones that feel the most comfortable to you. And practicing will help you learn to gauge where to hold the wire to make each bend (which can be tricky). The better you can handle your tools, the better your work will be. And the more practice you have, the quicker you can work.
After each bend, I'm constantly checking it against the model and plastic handrails (if availalble) to get the angles and lengths correct. I do have to occasionally re-straighten things and rebend it, and some wire pieces need to be tossed. But as you gain experience, you will need fewer rebends and tossed wires.
And the last tip off the top of my head for handrails is that I normally start from the cab, and work down towards the steps. It just works easier for me, but each of us has to find our own technique.
---jps