What happens to the corporate seal and minute book on closing day?

In a share sale, the buyer is acquiring the corporation itself, including its complete corporate history, so the minute book (and corporate seal, where the corporation still uses one — many no longer bother, since a seal isn't generally required) is handed over to the buyer at closing as part of what's being purchased. Your lawyer typically reviews the minute book during due diligence beforehand and confirms at closing that it's complete and up to date, or that any outstanding resolutions are brought current before you take it over.

In an asset sale, this doesn't come up in the same way, because the seller's corporation continues to exist after the sale and keeps its own minute book — you're buying specific assets, not the corporate entity, so there's no corporate history to hand over. If you're buying shares and the minute book turns out to be incomplete or disorganized at closing, that's worth flagging as a real issue rather than a minor administrative detail, since it affects your ability to rely on the corporation's own records going forward.