Last Saturday (2020-05-23), after reading this thread then discovering that Mark Wen and Amazing Auto LLC was located a mere 15 minutes away, I ordered two of Swivel No. 2 ("SW-2") at sprinterswivel.com (which, I note, is not listed today) for my newly-acquired 2015 Ford Transit 250. I also added installation to the order, which, strangely, had no additional cost to install that item. I suspect that it was an error in the catalog. (The other swivel models can be installed for $50 each. Installation is available only in the Seattle area.)
Once I received the email receipt, which said to contact Amazing Auto to schedule installation, I reached out and scheduled pick-up (and installation?) the next day (yes, Sunday).
I pulled into Mark's driveway at about 1:45pm. This was obviously Mark's side hustle that he runs from his home. In spite of Mark's broken English, it became clear the he was not aware that I had ordered installation. It was also clear that the installation fee had been omitted in their online catalog (which might explain why that product has now been removed from the catalog).
I used my phone to pay $50 per seat with PayPal to his hotmail.com address. Even before I completed that transaction, he was began the installation, starting with the passenger seat. I watched and took a couple of photos.
Had I done the installation myself, it probably would have taken three hours per seat. Mark installed the passenger swivel in less than an hour. The driver-side swivel took him an hour-and-a-half.
In general, I'm pleased with the swivels. They are the same swivels for passenger and driver sides. The driver side swivel is just the passenger swivel installed upside down. The driver side works exactly the same as the passenger side, except that the release lever always faces forward and does not swivel with the seat, and you have to reckon with the parking brake on a Ford Transit.
But I REALLY don't like the parking brake relocation. It puts a lot of stress on the parking brake cable housing. Using a small mounting plate (about 1/4" thick, triangular, about 4" by 6"), the parking brake handle assembly was remounted down about three inches, aft about six inches, and pivoted forward & down, allowing the seat to swivel while the parking brake was at least half-released. See the photo below.
That hard turn in the brake cable housing makes my inner engineer cringe. My next project: Remount the parking brake handle assembly so the cable runs more fairly into the floor. That at least means tearing down the driver seat and removing the battery box. Hopefully, I can just drill some new holes in the seat base, bolt the handle assembly using those holes, reinstall the batteries, remount the seat & swivel, and call it done. Worst case: I'd also have to drill a new hole in the floor and re-route the parking brake cable and housing. I'd have to crawl under the van to explore the implications of such a hole and re-routing.
In this photo, which shows the handle with the brake set, the hard turns in the cable housing are circled. The red arrow points to the only visible part of the mounting plate. The green arrow points to the plane of rotation of the swivel. The handle must be below that plane to allow the seat to swivel.