Hi Hamilton,
While HMS Compass Rose was fictitious, the shooting of the film was made on an actual ship: HMS Coreopsis, launched in 1941 and handed over to the Greek navy in November 1943, where she served at RHNS Kriezis. It took part in the Normandy landings in that guise. The shooting of the film occurred after the Greek navy returned the ship to the Royal Navy, in 1952.
Here is a reference on the above:
https://en.wikipedia.org/wiki/HMS_Coreopsis_(K32)So you could be guided in your quest by looking for photos of either vessel, depending on the period you want to depict her.
My dad served on her post WW II, circa 1950. I did a 1/350 rendition of her
http://www.modelshipgallery.com/gallery/misc/hn/Kriezis-350-gg/index.htm and gave it to him as a gift when he was 88 year old.
Happy modeling!
George