I've got a few sketches drawn up and uploaded to 3D Warehouse for my single-tier upgrade I'm in the middle of.
Single-Tier strut stand (work in progress, I've already modified past this)
Stand w/ the 15g Stout Kettles vessels I have on order
1"-1.5" Tri-Clover ball valve assembly
Inline Chugger Pump
3-Roller Monster Mill grain milling station w/ removable hopper+extension and handle
They're by no means commercial quality and some of the dimensions are from the factory spec sheets and/or eyeballing it, but that's stated right on the file pages. If you want these models or any other I make in the future you can search for them or just snag them from my profile at the 3D Warehouse