That part about being off by a fat 1/16 on every door really stuck with me, because that's the kind of thing you can't see until you're hanging cabinets and nothing lines up. I'm curious about the shellac step though. Did you do the edges before or after you glued and screwed the sled together, and does it matter which shellac you use? I've got a can of clear Zinsser sitting on the shelf and I don't want to waste a sheet of MDF figuring out the hard way. Also wondering if you sealed the faces at all or just the edges, since I'd guess the top and bottom breathe different than the cut sides.