I have these Marx train items restored to operation. The loco has old rough paint but the motor and E-unit work fine after cleaning and servicing. The side rods are replacements from something else, they fit OK. The cars needed rusty wheels and axles cleaned up, and I had to replace some missing wheels and couplers. These metal Marx cars have a lot of drag but the loco is fairly powerful. The die-cast tender is unusually heavy. The drivers are a bit short for a Pacific-type, but it's pretty deluxe for an old Marx!
That's got a consist similar to a Montgomery Wards set from 1954 - the L&NE hopper wasn't originally part of the set. Wards cataloged a lot of Marx accessories and separate sale engines and cars including the L&NE hopper. The 1950 catalog shows a tin litho RI FT pair like the Santa Fe #21 FTs - that would have been a gorgeous addition to the Marx line if it had actually been put into production. Finding boxed Marx 3/16ths cars is tough - very thin, easily torn cardboard equals short supply. Certain boxes are tough to find (L&NE hopper, SF/PRR cattle cars, all the flatcars).
Some later 333s came with smoke, but most I've seen don't have a smoke unit. They aren't the strongest pulling engines - if you can sneak in a little lead that will help the lugging capability. K-Line's reissue utilized a new mechanism that solved the pulling issue. The diecast tenders all came with super thin paint. It's unusual to find E or better shape tenders for a 333. I've seen a handful of separate sale 333s - they came in a brown cardboard master carton with a divider between the engine and tender. They weren't individually boxed.
As far as running those cars, the axles and wheels need to be super clean. Polish the axle ends, scrub out the holes in the wheels, and use Marvel Mystery Oil to lube them. I also wipe the bodies down with Mystery Oil as well - let it sit for a few minutes, then use old cotton t-shirts or towels and wipe the excess oil off. It will stop the rust from spreading any further, and get rid of some of the crusty surface rust. I've been doing the Mystery Oil treatment on tin 3/16ths bodies for 20 years, and it's safe to use.
