http://www.norbtach.nl/bouwplaat/Cont45h/Cont45fth.html is there a free program to resize these containers cutouts to n scale
Can't open the link, but both Microsoft Photo Manager and just inserting the photo into a Word doc allows you to change the size. Then its just a question of playing around with it until the scale is correct. Just work off a door (usually 80" height) and calculate for 1:160.
Download a copy of InkScape (free vector image editor), install it, then import the JPG file. You'll be able to resize it to exact measurements. All you need to know is the exact length of the container, then divide that by 160 and make the photo that size in the program.
I just copied the image from my web browser to Photoshop Elements. The container website says the correct width for N-scale is 122mm, so I used the Image > Resize menu and entered 122mm for the width. To make sure this was correct, I did a quick actual size printout to plain paper, cut the image out and taped it together, and placed it in a Kato 53' well car. Looks like everything sized out correctly: Jamie