Back in the early 1990s, a very obscure company called Black River Locomotive Works (actually a one-man operation run by Tom Jackson), produced this 4-4-2 based on castings of the Minitrix 0-6-0 shell and bits and pieces of old Atlas/Rivarossi 4-6-2 and 0-8-0 steamers. These were advertised in N Scale Magazine for a couple of years, after which Tom and his engines disappeared from the face of the earth. According to Tom, he was making them one at a time, all by himself. Supposition is that he sold a few hundred of them and that was it. They listed for $150 back in the day and have held their value very well over the years. In fact, based on recent eBay sales, they may actually be selling for more than that now.
Although advertised as a PRR E6, the drivers used on the model are incorrect (68" instead of 80") and the boiler is too narrow. Shell-wise, it actually makes a much more acceptable E3 (an earlier PRR 4-4-2), although the drivers are still wrong.
The tender is from the Atlas/Rivarossi 0-8-0 (just with the extended coal bunker removed). To create the locomotive, Tom actually cast the shell and frame and then made copies in pewter. The pilot/cylinder assembly is from the Atlas/Rivarossi 4-6-2 (screwed to Tom's pewter chassis). The engine makes use of surplus Atlas/Rivarossi 4-6-2 trucks, drivers, gears, etc. The motor is a 10 x 13 mm Sagami (equipped with a small flywheel) -
Both sets of drivers are geared. Left-rail pickup is provided by the left two drivers and the left two pilot truck wheels. Right-rail pickup is provided by the four right-side tender wheels. The trailing truck is electrically neutral. The tender trucks use axle wipers to collect current and a stiff wire on the drawbar to route current to the engine. The pilot truck is sprung. The pilot coupler is a fixed (dummy) knuckle and the tender coupler is a truck-mounted Rapido. There is no lighting. The wheel flanges are oversized, so Code-55 rails are not an option.
These are really silky-smooth runners with flawless pickup and sensational slow speed creepability (although the top-end speed is completely off the charts). Given the solid pewter boiler (along with the traction tire on the right-forward driver), they pull very well. The only downside is that with the small motor, they tend to slow down quite noticeably on grades - especially with 6-8 cars behind them. Note: they don't slip, they can pull the cars. But the motor is maxed out on torque, so it slows down. It has also been reported that over time the gear and driver axles in the frame can become wobbly and loose (pewter apparently not making for a very durable bearing surface). And yes, that old Minitrix-based shell is a bit primitive by modern standards. But overall, these are really outstanding, professional quality models - both in terms of looks and performance.