Often guilty of over thinking things, when it comes to odd things like this. But thought I’d mention what’s in my head anyway…just in case…I think I’d be tempted to have a look at the gear oil. Just to put mind at rest. Make sure all is well and no black looking, burnt smelling oil is present in there. Rule out it being as a result of rather serious levels of heat transfer. Looks very unusual to me, I must say. One of the pictures even looks like it has a lovely professional painted finish. The picture most recently shown after you cleaned her up..perhaps shows some colour in the stainless finish. This can be common on props in the budget end of the market…but can also be a sign of thermal transfer.
Just make certain there are no signs of arcing, caused by a circuit seeking its way to earth or ground. Looks like there are a number of bonding earth wires meeting there.
Anyway. Voice of doom here..sorry about that..but got it off my mind..you can do what you wish with it. All the best.