Just before BB went down i made an order using multisig escrow
I have no idea if the vendor ever saw the order, is there any way we can complete the deal if I can find a way to contact the vendor?
This was my first multisig transaction, so i'm not particularly wise to how it all works.
Yes, if you have either all three public keys (and your private key), or the redeem script (and your private key), and the vendor has his private key, you can absolutely complete the transaction.
Do you have the redeem script, or the three public keys? (Or does the vendor have them, that would work too. You both need to have them, but if he has them, he can send them to you and you can verify they're correct before doing anything.)
I can help guide you through it.