Well the Olympic looks exactly like the titanic
Incorrect: Titanic had a weather-protected A-deck promenade, while Olympic did not; Olympic had a tennis court on the boat deck, while Titanic had a cowl vent in that location, preventing her from having a tennis court; two differences visible from the bridge are that Olympic had a curved front to her wheelhouse, while Titanic had a flat one, visible in game; and that Olympic did not have Titanic's cowl vent #1 on her forecastle, but something else. From the exterior, one could see that Olympic had evenly spaced B-deck windows, while Titanic, again viewable in-game, had them spaced unevenly due to the fact that rooms are placed just inside of those walls. There are several other differences, but that should be enough for that point.
I also understand that Titanic may have been a little bit faster due to a slightly larger central propeller, according to an original source.
Not sure how correct they are, though.