That looks near identical to the no5 JB I got off the EE here. I paid $450. Professionally removed? Looks like clean work as does mine.
The only diff is mine retained the ears, no lug either.
I would have to imagine that it was removed due to accuracy issues/fliers. I however have never experienced the issue of a wandering zero that’s been stated about the no5. This has been debunked apparently.
I replaced it with an aftermarket piece from Numerich. They have a couple styles including a top ported cone.
I’ll see if I can post a pic of mine.