bobc,
I, too, have seen a slew of these in 458 with Magnaporting, but the manufacturer didn't do the work. I think a shop somewhere bought a bunch and did the deed.

One for sale here on this forum is purported to have "factory brake and knurled end cap" for when the brake is removed. It is a nice set up, but I do question the insistent representation by the seller that it is all factory. I had never heard of this, but thought I would ask the good members here about the veracity of the claim.

Still, it is a nice looking package, and I feel worth the $$$.