Going to sound silly but I just aged down all my favorite sims to toddlers and played them up to young adult. I have their young adult older versions in my library that I have been playing since release.
I just added my favorite sim and her sister (both vamp versions from my library) to the game and have downloaded most of the French clothing from the Oh So Roccoco site. I plan on having my Vamp girls and their human friends come to the future (sims present) to save their "descendants" (which is actually them in a parallel existence..Ha) from err maybe evil vamps or something. I have not figure out the rest but will by the time I start my game in about an hour...
....love the parallel existence theory..