After spending 3 weeks working on the main hull, I can say that stage is now firmly done. I applied some MM Lusterless Flat via the spray can to seal in all the paint and weathering work done so far. It also knocked down some of the residual Future gloss and unified the hull in the process.
The main deck consists of 3 separate parts so I removed those from the sprue and cleaned them up so I could do a test fit with the main hull to be sure I wouldn't encounter any problems down the road after it was permanently installed on the stand.
Everything plays nice with a snug fit into the hull, there will be some small gaps at the stern that I will need to address but nothing major. The wood decks will cover over the joins in the three sections so that's also not a concern.
I mounted the hull onto the stand posts and added the locking nuts. These were gently tightened and CA added to the top of the threads to secure them in place. I added a drop of CA accelerator and another dose of CA to cap it all off. That meant I could finally move on to Step 2!
Each of the deck portions has a raised planking pattern molded in place, so that had to go to allow the wood deck veneers a smooth and even surface to adhere to. This was sanded down with a sanding stick and the tighter spaces dealt with using a combination of smaller sanding sticks and the back edge of a #11 blade to gently scrape away the pattern.
Once that was done, the ten 5-inch guns that I had assembled earlier were snapped into position in their casemates.
Still plenty to do in Step 2 in terms of getting the deck side plates cleaned-up and ready for installation and adding other details.