@250rman the Lionel Maxi stacks containers are far from scale. Converting their measurement to 1/4 of an inch makes the 32.5’ scale- well undersized(no pun intended). For reference, here are some scale intermodal containers on a variety of different types & brands of cars:
K-line Thrall well car- 16.5.” Long. The well size is 40 scale feet so 10”. This Car is, at least in size and design, prototypically Representative of a thrall well car with a 40’ well. Unfortunately, this Thrall well car represents itself as having a 48’ well with the large 48 next to the APL on both sides. In addition, it further misrepresents the actual well length with markings that read “ 40’, 45’. 48’ “on the outside portion of the top of the well. That said, there are some K-line Thrall well cars that have a 40 on the outside and thus accurately portrayed. The bottom container is a K-line 40’ And top is an Atlas 40’
Menards well car- 17.5” in length. Well isTwo slightly modified Weaver 20’ container in the well, Atlas 40’ container on top 
again the Menards well car. The Menards containers are undersized(19”). Bottom containers are ROW 20’, although they’re exact measure is closer to 4.9. Regardless, the left side of the well car shows how the Menards 40’ container is too small for the ROW 20’ containers. 
Atlas 40’ container or 2 RoW 20’ Containers. There is a slight gap in the middle
from left to right: Weaver bulkhead, modified to fit an Atlas or K-line 40’ container. The next 2 flats are K-line with removabal bulkheads. THe middle k-line flat has one Weaver 20’ And on MTH premier 20’, the last car to the right has two 20’ Weaver containers. Weaver containers have been modified- removed the bottom(as it has protrusionsthat make them incompatible with the other well cars and flats) and replaced it with the ROW bottom after drilling holes in the corners of the ROWs(replaced their length with thick styrene)
