Ask around for a member of MEDx. It is a newly formed guild made specifically for coordinating for this event. Working with them I’ve opened over 20 of the bags rewarded from saving 1200. Granted, the only LS items I’ve gotten are Dragon Coffers which had maybe 25 Zhaitaffy and some fireworks. Since they lowered it from 1500 to 1200 there’s strong evidence that the loot table was very watered down and your odds of getting anything nice from a previous LS is next to nil.
That said, if you want to try, MEDx guild would be what I’d recommend.