Just some more pictures I thought were fun. Here's some pictures with a lionel gondola and model power O scale figure vs a lego brick built gondola mounted on mpc era trucks with a lego barber.
Obviously the minifigure is boxy but the car size looks great. Imho
This is a comparison between lego truck assembly vs another mpc era truck assy.
You can see the difference in gauge clearly in the last picture. This is only one type of Lego train axle, but it is very common. BMR uses a different style that allows for mini roller bearings. The lego train wheel is pretty close to an O scale wheel. I have some 2 rail scale trucks somewhere but I couldn't dig them out this evening.
Anyway, I just thought think this is fun.
