Thanks for the prompt response. I actually just happened upon the answer (and have the same link in my clipboard to paste here actually). What about a case where the lockbox definition is lost on the organizing machine and neither / none of the others imported the definition? Is there a way, without the definition, to restore the lockbox? Let's assume the cases of you know the public keys / addresses that were originally used to create the lockbox, you know one key that was used to create the lockbox, and the rare case that you can't remember which key was used to create the lockbox (but maybe you know which wallet was used).
Know all keys: Just create another lockbox that uses the keys. That's all you need to do.
Know only some of the keys: Uses the ones you do know and keep trying to build with the others. For example, let's say you know that a wallet with 20 addresses in it was used, but you don't know which address was used. You'll have to cycle through the addresses until you find a lockbox that works.
Know no keys: You're out of luck unless you know the wallets used and are willing to try hundreds, thousands, or possibly even millions of address combinations. (3 wallets with 100 addresses each = 100 x 100 x 100 = 1,000,000 possible combinations.)