I'm pretty sure we can name a bunch of super old names, but I'm not sure where they would necessarily lie in the "history" of SL. Unless we had some kind of memoir for older people.
As you have already mentioned plus some extras: Sriracha, Yondaimethethhokage, KBoogi, WhiteEyes HiashiHyuuga, Leet Ninja Kurenai and Mizuki, Tehbeastjeffsays, Academy Dropout KawazoeTakumi, Mihamaru, RinoaHeartilly, Xiao, Tsunumi, Lebis, PerfectFlaw, KingCyrus, Klaymank, Isai, Taumaster, Kurisu, Klaymank... and the list goes on. XD