You would really have to look at each side by side to see the details, but the 1999 bikes have parts that are very nice reproductions of the original parts. The frame, springer fork, tires, pedals, seat and sissy bar are very nice reproductions and look very close to original parts.
Actually, back when the 1999 reproductions were issued, they also issued the parts used for the bike as replacement parts that could be bought over the counter for your original bikes. The parts looked like the originals and a lot of people use them for thier bikes. Especially the fenders, where originals were difficult to find at the time.
The newer reproductions just generally have cheaper, non-original looking parts.
Do a Google search and look at pictures of the 1999 reproductions and the more recent reproductions and you'll see the difference. Look at things like the fenders, pedals, seat, sissy bar, etc.