Time is the big part. I would guess that Mike had 10 hours total.
Cleaning the old one off, I would recommend lots of carb cleaner, then seal it up and media blast outside.
here is link to how I seal them up and then blast them. My goal is to get as little sand and media inside the cover, as there is a huge air gap that you cannot clean out.
@2fpower If @ariff is getting everything together he can jump ahead of Cyclops. I've got a few trips, a bunch of paying gigs I've had on hold and a laundry list of things to do to Lexi first so I probably won't be ready to jump in till about early Jan.