This week I picked up an IBM Tower ( Model 80 from 1987 ). The foam or insulation or whatever you want to call it - is toast. It seems to have deteriorated beyond anything I've ever seen. Isopropyl alcohol doesn't do much to clear it. I suspect theres also some chemical reaction from the green tape maybe, to stick it on.

Its at 3:28 and 3:54 in the video.

https://youtu.be/ds7yDoVScqA?feature=shared

I've got a good chunk of it off, but given what's in this case, I'd rather not take it apart to clean it, if i can avoid it. Anyone seen this before and can suggest something? It turns to powder when it comes off, but then if you touch it, it leaves an oil smear. Very strange.