As I already mentioned on this forum - I have longest 66' gondola from Lionel and love it from day one when I purchased it in 2017.
It is loooong and very good shaped. Wow!
Few loads clicks in my head immediately. Probably first one is construction demolition load.
Here sky is only limit - you can add as much details as you can: sure,
- cut shaped lumber should be present - old and rusted one, new one, green pressure treated one.
- broken sheet rocks panels (light green - if it is visible on images?),
- tiles from bathroom, probably this can be present as overall mass
-steel mesh from reinforced floor in bathroom,
- few stones marble
- probably few wood branches
- something green (I think it is old wall paper from children room)
- old rope an chain from heavy weights,
- carton boxes from new TV and gas stove
- rusty metal pins and panels
etc.
Please let me know your thoughts