Well, I've made some progress, slowly but surely.
We got through with our vacation travel, and finally had enough money to get to a "useable" point with the pens so we could tear out the old ones and get them living in their new digs.
So far out of the 32'x32' area, 3/4 of it is now in use by the turtles. The front corner pen in the photo is missing a wall section. That pen is where we are going to start digging and install an 8'x16' pond, which must be done by the time it's finished. The wall section was left off so we can get a wheelbarrow in and out more easily.
Of the rest of it, there are four 16'x8' pens and one 16'x16' pen. They seem to be enjoying having at least doubled (and in the big pen quadrupled) their space.
I can't wait to finish the pond, so I can move the aquatics to that pen, then I will use the one they are in for a spare.

album of photos of new pens



, and on the interior walls it's a 2"x6".