For a Coopers Home Brew Kit-are the air plastic bottle cap lids reusable if the air lock seal is not in them?!
Answers: Also if not or - does anyone know where to buy more lids at?
I've always reused my plastic lids and never had a problem. That lock seal is commercially made on all plastic lids because they are usually used for the soda industry or bottled water, and are used to show if the lid has been tampered with. On your home brewing, unless you don't trust the folks that live with you, there shouldn't be a need for the "tamper evident" seal.
As long as the lids haven't been damaged any, and still hold a good seal, you can keep using them.