Weaver and Williams both did brass imports in 2 and 3 rail. And yes the compromises for 3 rail were made. The most visible were locos with 4 wheel lead trucks. They seemed to make the pilot decks and trucks longer to allow them to swing around the cylinders on sharper curves.
You can still find many of these 3 rail brass locos at shows and on ebay. Just add the electronics of your choice. Weaver did about 2 a year for 10 years. Williams did a bunch of USRA stuff and others.
Right or Way models, another small 3 rail company imported brass models only in 3 rail.
Carworks brass diesels use Weaver drives, now P&D Drives. You can buy 3 rail wheelsets from P&D and easily convert them. The gearboxes unscrew apart. You do have to add 3rd rail pickups. Carworks did a bunch of FM models and Alco models.
So there has been a lot done in 3 rail in "nice" brass.
Remember brass is pretty much still hand-built and imported in much smaller batches than the diecast or injection molded stuff. Therefore it is generally not warehoused or inventoried. Product is often sold out by the time it gets into the country which is starting to happen to other stuff too.
