I have one of the older Bachmann 4-6-0’s and the outer insulation on the tether from tender to loco has started to get very stiff. This is putting a lot of stress on the wires, connectors and the sound on/off switch. Do you know of any products such as Armor All, etc that may help to restore some of the flexibility to the insulator ?
I wouldn’t recommend Armor-All because it dries out and stiffens the insulation even more. Car washes here discourage the use of Armor-All because long-term use causes tires to crack.