Thanks Bill and Ed for responding. Ed, it is a white fibrous compressed
material. Now, true it could be other things but my educated guess is asbestos.
What else would look like that and appear on top of a fiberboard bottom panel?
No matter, I assumed the worse case and sealed it. If it is anything else,
better safe than sorry. Oh by the way, the radio is recapped and working
well.73, Mike KF6KXG