I have had my eye out for a few years for one of those. Only 1 has appeared since my hunt has started and it went to Drew P at Air Fuel Spark.
I have looked at various ways of making a 3x2 setup happen with other intakes. I tried to modify an Edelbrock 2x4 air gap intake but a bunch of welding would have been required, it looks promising at first glance.
Carl had one remaining on his shelf about 5 years ago when I called, it had been powder coated black so I passed on it. Really regret that.