Try and put labels on what is in the bins and on the shelves.

You'll want your (dust free) oils section with oil, grease filters ETC.

Then probably an electrical section,

Maybe have sections for each machine type, tractors; cultivation, planting, harvesting etc. And within that section try and keep to specific machines. most used at the front, relics at the back.

Mezzanine floor for more efficient use of space? Lighter stuff upstairs.