Hi Dan
I have never come across a maple wood stain or paint but it is possible to get the normal Ronseal wood stains but there mostly of the hardwood variety and probably too dark.
Another idea may be to use Danish oil as this will darken down the wood a little but seal it aswell or maybe look at drawing inks from an artists shop could be another way to go.
regards
Andy

Hi Dan
the original wood used on the Yamato deck was a Hinoki cypress wood which when brand new has a look of dark pine to it but after weathering it turns more grey in appearance, before the Yamato's last voyage her previous assignment was a night mission and it was reported that her decks were painted black for this mission and then cleaned up after the operation by the crew but there is a lot of conjecture about wether this happened or not. Even Yaturo Honma from japan says its a question that's talked about a lot with modelers in his country. My thoughts on the deck would be that an underlying grey with traces of paint from the night operation would be present
So you have a couple of choices here you can just leave the planking the colour it is as its glued in place and use Danish oil or a coat of varnish to seal it or send for that stain but im not even sure its legal to import it with the customs regulations as they are at the moment.
What I did to my Yamato was to use a Rowney artists ink called 'cool grey' which will give an overall grey colour but still shows the grain ,this ink can also be watered down to give a lighter shade, after the grey had dried I used Tamiya's smoke to give the staining from the black paint. I have attached a pic of the Mikasa's deck which also has Hinoki cypress wood deck ,the pic was taken when some of the decking was being renewed with new wood so a clear difference between the old and new wood is quite clear, hope this helps Andy