Well, the machine is finally taking shape! This week I was able to get the y-axis rails and the x-axis gantry mounted and squared up to the table.
The main difficulties were dealing with a few slots that didn't line up perfectly with the threaded holes at the ends of two of the rails, and squaring the end plates to the rails. The former truly wasn't difficult just a necessity, and the latter wasn't too hard to accomplish with a bit of shimming.
I'm quite happy with the progress I've been able to make, and I'm thinking I'll have the machine running under its own power by the end of June. Hopefully that's not too ambitious.