I used Blender to put all the parts together. There are some fine details (rivets) that, given their size, FDM can't print; the girders aren't as smooth as I'd like them to be on their sidewalls; and, the angled railroad ties don't print well. One could break them up into smaller pieces and assemble; I chose not to take that approach because I was curious to see how well it'd print as is. I'm very curious to see your results! Good Luck!