After all that's been said (I did sort of go off on a binge there, sorry), the decks on wooden ship models are actually one of the easier parts of it.
The hardest parts are getting all the guns right, and doing the rigging. Both are extremely repetitive and you can work for days without any readily visible progress to anybody but yourself, while the decks you can see progress ever after a few minutes of work. And cutting and laying the planks is fairly easy. Especially when you use a veneer plank that's already to scale, like I described. It doesn't matter then what the underlay is, since you only see the top veneer part.
So, to tie all this back to the Ernest's French cannon, and a few things that could improve the model if you ever do another one. (Not that it doesn't look really good, it does. But just a few inaccuracies)
The deck shouldn't be varnished as it looks in the picture. It could be just the lighting, but it should be matt finish and uncoloured.
In that scale, you should definitely be able to see the caulking in the deck. Probably also a few butt joints, since gunports were always positioned to have the weight of the gun over top of a couple of beams.
You could also put in some treenails wherever the deck crossed a beam or where butt ends of planks met. Treenails (or trunnels - there's often more than one spelling in old nautical terminology) are basically wooden dowels used in stead of nails since dowels don't rust and when they get wet, they swell and are stronger than metal nails. They often had the ends split and little wooden wedges put in like an axe handle, but you couldn't see that at this scale.
There's a ringbolt near the back of the carriage, just in front of and above the rear wheel, that the tackle to run the gun up to the port is attached. This ringbolt should be horizontal, not vertical, to reduce the strain when the gun recoils back.
That 'run-up' tackle should go outside the breeching rope (The heavy rope that goes from the bulwarks to the cascabel of the gun). Lines should never criss-cross if at all possible, since if they can foul each other, they invariably will. and lines that cross each other will cause friction and wear the ropes. Definitely not something you want when a 2 or 3 ton piece of iron is lurching back from a shot.
The cotter pins on the wheel axles look kind of large. That's probably the kit but I might have replaced them with something smaller.
The gun barrerl still has the flashing showing at the seams where the mold came together. Probably something that couldn't be corrected though because it might have spoiled the finish on the barrel, so something you just live with, especially when you had such an incredibly short time to do such a nice piece of work.
The cheeks or side of the gun carriage should be cut into a minimum of 3 or, as looks in this picture, maybe even up to 5 different horizontal pieces of wood. It just wasn't possible to make a single, flat sheet of wood strong enough to take the shcock of recoil, and so they used several thick pieces stacked on top of each other. The steps in the back of the cheeks indicate how many pieces were used in this carriage. there should be bolts on the top of each one of the steps at the back of the cheeks, and another at the very front of the cheeks to tie all these pieces of wood together.
As well as the sponge laying on the deck beside the gun, there should also be a couple of handspikes, one on each side. These were sort of like wooden crowbars used to put under the wheels and then lifted up to slide the carriage one way or the other. that was the only way they had to traverse the guns other than turning the whole ship.
Does the sponge have a "worm" on the end of it? A worm is a double helix, sort of like a wine corkscrew, that was used to extract shot from a gun that misfired.
There should be a touch-hole at the top of the gun near the breech, to fire it/ This is just a hole drilled down to the powder chamber.
Spare ringbolts on either side of the gunport, horizontal again. These were used during storms to lash the gun to the side of the ship. If you didn't do so, this was where the term about somebody being "a loose cannon" came from. You definitely did not want a loose cannon on a ship bouncing around in the waves.
Keep in mind Ernest, I'm not trying to be disparaging. I think you did a great job and the cannon looks wonderful. It's meant to be a decorative piece after all, not the super accurate model like all of your U-boats. These are just things to keep in mind should you one day try your hand at a tall ship build.
You can see why some of those sailing ship models often take several years to build. Also I guess where I decided to build my own U-boat deck out of a couple of thousand pieces of wood. It's actually not too bad compared to some of the wooden ship decks.