hi there have you had a look at the Masterclass build at the 63ft Whaleback which I built?
You can see that I painted the decks grey - this is because, during the early part of the War (1940=42, a lot of these vessels had a bright yellow, or what is correctly termed 'dark cream' for the decks and superstructure tops.
However, after these vessels had been repeatedly shot at by both British and Germans/occasional Italian air force, they went over to dark grey colour decks and superstructures - some of them, especially the Whalebacks left the Bridge roof a dark cream.
Also, not all of the vessels had the 'chequered marker' on the bow, this is an RF indication - but, in places such as Africa/Malta, some of these vessels had a cross on the foredeck. The weapons carried by these vessels varied considerably upon whereabouts they operated, and, you will find that vessels who operated in the English Channel were indeed heavily armed with any weapon they could lay their hands on.
aye
john e
Bluebird