I have recently bought a MISB set. It's a set released in the year 1983. When I got the set, one flap was already loose. Due to old age those seals sometimes tend to fail, as we all know. So I pulled the carton box out and noticed that there was a kind of substance on one or two sealed plastic bags. It is white and sticky. That substance was also on one stud of a bigger element in the box - some plastic bags lie on it -but I could easily wipe it away with my finger.
I'm wondering what it is. It looks like sticky white paint. Upon contacting the seller he could assure me that both seals were intact when he got it, and he said he had never had a look at its contents, thus not knowing anything about the matter. I believe him since I've bought things from him before.
Unfortunately, I cannot post any pictures. My cameria isn't good enough so that you'd be able to see what I am describing.
So my question is whether you have had similar experiences. Have you ever had a MISB set in which you found dirty plastic bags matching my description... or have you come across other peculiarities with older MISB sets?