Actually, planking the deck of this particular kit isn't as difficult as it may look at first glance. I did it on the one I built about thirty years ago. The designers (probably unintentionally) made it relatively easy.
Normally, the big problem would be to contend with the extra thickness the planks would add to the plastic deck. But take a look at how the decks (both spar deck and gun deck) are mounted to the hull halves. Inside the hull halves are some big horizontal pins, which support the decks. The pins are mounted in pairs, about (if I remember right) 1/8"" apart. Molded on the bottom of the deck components are a series of vertical pins, which fit between the ones on the hull halves. The interesting thing is that each pin on the underside of the deck parts sits in the middle of a flat plastic "pad," which happens to be just about 1/32" thick. In other words, the mechanism for mounting the deck consists of a series of T-shaped projections on the bottoms of the deck components, mating with horizontal pins on the hull halves. (Just why those pads are there I don't know; maybe they correct an error earlier in the design process.)
Shave off the pads with an Xacto knife, and the whole deck assembly drops by 1/32". Plank it with 1/32"-thick basswood, and it's back up to the proper level. (You'll have to add 1/32" strips to the tops of the hatch coamings and other projections too, but there aren't many of them. Revell made just about all the deck furniture in the form of separate pieces.)
I used basswood on mine; if I were doing it today I'd use holly veneer, but basswood is much easier to find and actually works pretty well. Another tip: before you lay each plank, run a pencil around the edge. That will produce a fine, dark grey line to represent the caulking, and can't be removed by any subsequent scraping or sanding.
On my old model I used Revell tube-type plastic cement (now, alas, no longer available) to stick down the planks. It was good stuff; it softened the surface of the plastic and soaked into the wood, making a good, solid bond. The only widely-available tube-type plastic cement currently available seems to be that stringy, too-fast-drying Testor's stuff. (I can remember the days when Testor's started mixing oil of mustard into it, to ward off glue sniffers. It hasn't been the same since.) Whether that would work satisfactorily for wood/styrene joints I don't know.
For a finish, I like the "Driftwood" color wood stain sold by Olympic Paints (available from places like Lowe's), followed by a coat white shellac, diluted almost beyond recognition with denatured alcohol.
If I remember correctly, planking both those decks, once I'd laid in the necessary quantity of basswood strips, took me about two evenings. A pretty modest investment in time for a big improvement in the finished model's appearance. And probably not much more time than it would take to eradicate the awful joints between the deck sections.
Maybe I shouldn't mention the following point, but in my much younger years I missed the other big problem with that kit: the fact that the hull sides are too thin. That really isn't Revell's fault; with 1965 technology it probably wasn't possible to make them any thicker without introducing major problems with shrinkage. If I were doing the kit again (gawd forbid) I'd try to fix that. It wouldn't be hard to add some plastic strip around the edges of the ports on the gun deck, but the spar deck bulwarks would be a bigger problem. I'd be tempted to ignore that one.
Good luck. It's a great old kit.