That is going to be fantastic. Nice subject, for sure.
The most obvious difference, to me, from her sister, and it's a big one, is the (ahem) greatly increased number of lifeboats. There appears to be a continuous row along each side, perhaps as many as 14, rather than 8. Some pictures show them swung in, others out.
Plus aerial views show quite a few additional boats on the decks.
I'd guess a donor kit would solve that nicely.
Two tips. Locator pins IMHO are never useful at all and I always shave them off on my aircraft models. It's a gamble if they're right, but if they're off it makes alignment impossible.
Second, be sure to put a full height vertical divider in the hull from stem to stern. The ports are great opened up, but you do not want to see through, it'll ruin the whole effect. I learned this building model buildings. Lighting would be a great project.
Great model, keep the post up!
Bill