There's a thread with all Lead locations in the Player Guides forum section.
https://forums.elderscrollsonline.com/en/discussion/524115/antiquities-leads-lead-locations-uber-thread/p1
I recommend that everyone post their findings there rather than in individual forum threads, so that it's easier to find everything in one place! Thanks for sharing, and happy Lead hunting!
I got mine yesterday. But I did feel just a tiny bit bad about leaving the fledgling griffon next to the body of it's Mom/Dad that I just killed lol. We should be riding these majestic beasts, not slaughtering them for a shiny feather =P