7. Hot glue the braided pair of wires to upper interior of boiler.
I used hot glue on a loco once. It remelted from the motor heat near it. Same near the bulbs. I use silicone or flexible household clear epoxy now. The radio shack epoxy is very similar, flexible, cuttable, and sometimes pealable.
Walker- a heat sink can work wonders "speading" the heat on rectifiers, Ive added them to quit a few cabnet style video games to avoid elbow burns. Those can get hot enough to blister you sometimes. Away from wires, plastic, or hot glue

it really shouldn't be an issue.