We prepped everything on Wednesday. It was below freezing and really windy so we hid out under the lean-to at the end of the shop. Precut all the joists and sheeting. Then built the 2 skids. I punched 2.5" holes at each end as grapple points if it ever needs to be moved.
This morning we recessed and leveled the blocks. The skids are there temporarily as a level surface.
The platform as you currently see it is upside-down. Brackets are in place to attach the skids before we flip it.
3/4" sheeting goes on top. R21 insulation fills the void.

When the only tool you have is a hammer every problem starts to look like a hippy.