I finished this as well, today. Don’t mean to spam the forums, but figure I’d upload it while it’s fresh on my mind.
Areas that made me struggle:
The RAMP. WOULDN’T. EXTRUDE. PROPERLY. I almost lost my mind, haha. The steps and the normals of the ramp were all, independently, backwards. And I had to manually reset the normals, as they weren’t fixed by the outside algorithm. (Edit Mode -> Mesh -> Normals -> Flip Normals)
When I was playing around with the top part, I couldn’t separate the part easily until I shift clicked vertices, edges, and faces in the bottom toolbar. Circle select and wireframe made that much easier to separate, duplicate, rotate, and rejoin.