Here is a view of the bottom of the wooden thingie. There are no threads. The missing shards of the CD 700.1 could not be found.
Answer: Probably not an insulator... the "pinhole" for an insulator this size should be one inch or less in diameter. Looks wider. If it is a wood cover for an insulator, a matching glass insert has not turned up yet.
First picture [id=112456794]