Oh wow! Thank you for rescuing. Boy, do you have your work cut out for you!
If I were you, I'd ask a Lab rescue to help with placements. You may even be able to turn them over to the rescue and foster them. That way, they can pay for vet care and be reimbursed through the adoption fees, but also, you'll have a whole team with experience to help you pre-screen, homecheck and reference check potential new owners, plus a contract in place with spay and neuter policies. Something to consider!
Good luck!