Omelets. Eggs. Quality is quality, there is no such thing as "reduplication" merely refinement and the achievement of perfection.
"IF" you can (within a reasonable frame of reference) get away with recycling AND make it look good, GREAT. But if it's going to take a lot of effort in either case, then go with something new. Otherwise, who's going to notice that the model is any different when the maps has no changes to the details other than to try and fit it in? For several ships already I've had to delete the existing normal maps because they were made for pre-higher poly models. If those ships had been remapped instead with NEW maps, then the replacement textures would have gone in with the models and there wouldn't have been a need for discovering "oh wow, the old normal maps actually make it look worse" _after_ it's now out and about.
There is a BIG difference between retaining the retail elements of appearance, and slavishly adhering to recycling the Retail maps (or stitching retail tiles into a unified texture) that I'd like to make sure doesn't become a habit. Because while it may not be a BAD habit per-se (if done right) when it goes south, you have the issue of people going "wait, that got upgraded? I thought that was still Retail" which means we've failed at providing the necessary aesthetic of providing an upgrade.