The snow plow and tender were scrapped at Pacific Steel and Recycling (the new, politically correct name for Pacific Hide and Fur) not only because they were sold to Pacific, but also nothing was wanted off of the equipment---Once Pacific gets it, there is no going back and getting pieces, they get it, all of it, and cut it all up. The locomotives in question were parted out, something Pacific doesn't even attempt.
LOAD BOXES--generally made out of dynamic brake grids---these days SD-40's or SD-45's are the favorite. They are used to simulate loads on the generator/alternator of a locomotive to see if it can produce at capacity. In a nutshell, the produce the load of the traction motors, enabling mechanics to see how it would work under load without taking it out on the road.
EMD locomotives -2 or newer with extended range dynamic brakes are able to self load test at the flip of a few buttons. GE units have similar features. Quite often, high voltage generator/alternators seem fine and only fail under heavy load when things like weak insulation and brush flash-over begin to show up. Load boxes simulate a load in order to help these and other problems show up during trouble-shooting. Load boxes can also be used after a unit has had a class-one overhaul---a load is simulated to test the unit and to burn in the brushes if so required. Some shops used to load box a unit for several hours after a class-one overhaul to make certain everything o.k. and not going to fail.