I noticed a similar topic back in 2013, and decided to let you know what I've done these past few weeks. I had some container graphics I gleaned from the WEB over the years and modified them from 40'l x 8'w x 8'h to a taller version 40'l x 8'w x 9'-6"h. I also converted some 20' long containers to 40' by simply extending the ends. I found some scrap styrofoam that was exactly 1-1/2" thick - which equals 8' wide in 'S'. I had also borrowed a foam cutter from my son which allowed me to cut blocks of styrofoam 7.5"l x 1.5"w x 1.78"h. (a 2x4 could also be used since they're 1.5" thick, but would be much heavier. You could rout a lot of the center out with a router, leaving some cross-struts along the bottom.) The styrofoam I used had a clear plastic cover which showed through the paper printed container graphics. I solved this problem by putting a thin coat of spackling compound over the clear plastic, as well as other areas of the foam that weren't perfectly flat. I then sanded the excess off. The result was a nearly perfect block of spackling coated styrofoam suitable to use as the base for the applied paper container graphics.
I developed the following container graphics:
CHINA SHIPPING 40’ 1/64 (S)
CMACGM 40’ 1/64 (S)
EVERGREEN 40’ 1/64 (S)
GENSTAR 40’ 1/64 (S)
Hamburg Sud 40’ 1/64 (S) - faded
Hamburg Sud 40’ 1/64 (S)
HANJIN 40’ 1/64 (S)
Hapag-Lloyd 40’ 1/64 (S)
HYUNDAI 40’ 1/64 (S)
IFF 40’ 1/64 (S)
IGS-HANSA 40’ 1/64 (S)
K-Line 40’ 1/64 (S)
MAERSK 40’ 1/64 (S)
MAERSK SEALAND + P&O Nedlloyd 2-20' 1/64 (S)
MAERSK SEALAND 40’ 1/64 (S)
MAERSK SEALAND 2-20' 1/64 (S)
MSC 40’ 1/64 (S)
NYK 2x20' 1/64 (S)
OOCL 40’ 1/64 (S)
P&O Nedlloyd 40’ 1/64 (S)
P&O Nedlloyd 2-20' 1/64 (S)
UNIGLORY 40’ 1/64 (S)
I've got a couple Des Plaines Hobbies 'S Scale America' Husky Stack well cars that look GREAT. I'm also trying to use some American Models Intermodal Spine Cars, but they need a little work ad they're not set up for containers, only semi trailers. (Another one of those 'round-tuit' future projects.) In any case, I'm attaching some photos. If you're interested in getting some of the '.pdf' graphics files I've made, just let me know.