I'm posting this to some of the busier tribes I'm in, or to tribes whose subject I particularly like and want to resurrect:

I apologize for ALL the crossposting I'm doing about this, I just want to get a sense of where the active people are, and maybe encourage a few people to join tribes they're not in already. I also want to learn about more tribes for me to join. I also think that it'll bring up some 'related tribes' about similar topics.

So:
what other tribes do you like?
What do you like about them?
what do you talk about?
How off-topic do you get?

what 'dead' tribes would you like to resurrect?
Do any of the dead tribes have new-member access problems (like a missing moderator and private or moderated status)? Either situation can usually be gotten around by having members give other members invites.

Would you be willing to invite people to this 'locked-down' tribe if the current moderator's AWOL?

How to give people invites to a tribe you're in that isn't public (short of replacing the current moderator, which can be done):

Visit the member's profile whom you'd like to invite
click 'see more' button that is right below their profile picture
Select 'invite to tribe' in order to send them invites.
You can now send them invites to three tribes (that you're a member of already) at once.