Those things were CRAZY!! They had a dime (as in coin) in them that the allen screw pressed on. The dime sat in a little cap, kinda like a furniture leg cap. It was just a real thin sheet metal deal. The allen screw was drilled through and in many cases it didn't intersect with the side drilled hole and you wouldn't get boost reference. Hopefully, if they are still available, they have improved the system.
Do you want one so it will pass emissions, or do you just like the stock look? If it is for emissions reasons, just install a 233 Bosch when you go through, then swap it out when you get home. They change out in about 4 minutes. I have one of those all cut up. That's how I know what they used to make them.