Copper blob on transmission drain plug?

[johnking]

I have a newly acquired 1965 Massey 1235. I was looking to drain the tranny/rear end and the drain plug looks to be stock but has a blob of copper type substance on the surface of the hex head. I scratched the gunk which I first thought was epoxy but the scratches show it to be metal. Why would this be there? The rear end drain plug looks unaltered. Is this an old way of saying do not touch or warning of impending doom?

 

[Soundguy]

sure you are not seeing braze?

post a pic if unsure

 

[MIKE R]

If it is a braze it will be more likly brass not copper. Brass has a more yellow color to it than copper which is more brown. A photo is worth a thousand words.

 

[Soundguy]

whens the last time you saw melted copper blobs ?