On the other hand... not everybody checks their email every 2 minutes like me. Would it be rude to email them again and say "Not heard from you ... please tell me who to make the cheque payable to" etc.?
On the third hand... you'd think if somebody only takes cheques it might occur to them that their buyers need to know who to make the cheque payable to, FFS. And that they might make a point of checking email just after a sale.