Saw this in an old insulator guide:

"An Insulator Book for the Advanced Collector" by James L. Hill, copyright February 20, 1969

Interesting the title inside the book says "An Insulator Book for Advanced Collectors". I would guess the latter is the correct name as he notes he also produced a book "An Insulator Book for Collectors"

Nickname: Knobby. Invented and patented by John C. Barclay, chief engineer with Western Union. This insulator is extremely rare.

Price $35.00 up

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We all know about the CD 147 embossed BARCLAY in Lynn R. Stuart's early book. An exact drawing of a CD 147, but clearly depicted as embossed BARCLAY. We have always wondered was there a CD 147 embossed BARCLAY (certainly possible) or where they perhaps talking about the CD 150 embossed BARCLAY? However, the only one known in the hobby today was not found until 1987, 20 years after the book was written. That one came off a pole and not from a collection. Of course back then others could have existed and who knows where they might be today? Either one of those cases are certainly possible.

Then I happened to see this... what is this piece? The standard style CD 147 that we are used to is also shown in the book so this is not some odd rendering of that. Looks like some of the dot/dash pattern on some of the Wade style insulators, but these are at an angle. I don't know how you would even put a tie wire around this piece? ... At the moment, I don't even have any speculation about this piece.

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Update: This insulator is an exact copy of a variant of the CD 147 shown in John C. Barclay's patent. Here is a [id=467210771; comparison of the two drawings].