Man, some of the suggestions in this thread were pretty scary and some
were pretty sound. I'm not saying which was which.

On the scary side of things, I'd like to brain storm the following:

Anybody remember the Henry Reed series of books? There was one where
he suggests using blocks of ice to slowly lower a metal swimming pool
down into its hole because the crane became unavailable.

So I am thinking, what if the mill cart had one side that was bolted
on. Then you could slip the cart under the mill while it was up on
the wood blocks (assuming enough clearance) and then bolt the side
back on - weld it even - and then lower the mill onto the cart.

Ice blocks optional.

Jay