Greetings!
I am in the process of building my 2nd Tamiya 1/350 Bismarck and ordered the new KA wooden deck set from Hobbylink in Japan. Price was as expected and the shipping was not too pricey. The web site quoted 3-5 weeks for SAL but arrived in under 2. I also bought the replacement metal barrels for the guns from them.
Looking at the instructions the decks need some small fittings removed prior to installing the deck but after that I did a trial fit and it was excellent. When I am ready to install it will involve removing the adhesive plastic covering on the back of the wooden deck and simply laying it down over the plastic deck.
With the slightly different shades on the individual timbers I will probably leave the wood unstained.
I am sure the KA Deck for the Revell Bismarck will be just as easy.
I mentioned the deck colory since I just purchased the Academy 1/350 Graf Spee Premium with the wooden deck included and that deck will need some light staining as it is quite light overall....just for your info.
Hope that helps a little but I am new at this as well.
Cheers!