They are separate props and they're all in the collection which is linked in the description.

For some reasons none of the tenement buildings im subscribed to have the fire escapes on them. Is that by design or did it not download properly?

This asset (like most) was 99% completed for months and just needed some testing and screenshots. I tend to procrastinate when it comes to the final testing/screenshots/thumbnails and just do 3 or 4 assets in batches and upload them to the workshop back to back.

Mate it is beyond me. how you get such high quality optimised assets back to back out.