The cabin is a suite (aka deluxe cabin). There are no deck plans available for the actual ship, so the layout is derived from the RMS Queen Mary, which was built around the same period and had a small quantity of suites on her main and 'A' decks. There is evidence that the Asama Maru used the same method as well.
I was thinking of using 18A because 8 is an auspicious number. Please correct me if I'm wrong or can suggest a better one. One site indicated Ni for 2 as a hotel room number. Unfortunately, the chart only went up to 10. Following that lead, there were two different versions of 18, jû hachi and juuhachi on different sites. Are they correct? Which would be better?
What about 'A' for deck designation, would it be pronounced 'A' or... ?
Googled the following: "Pronounce room number in Japanese," "Japanese hotel phrases," "Ship cabin numbers in Japanese," "How to say deck a in Japanese," "Pronounce ship deck A in Japanese," "How to pronounce 18A in Japanese," "How to say letter "A" in Japanese," and "Japanese alphabet."
Your help would be most appreciated. Thank you.
eta: The members of little_details are awesome! Thank you everyone!