is it possible to un-cancel a sales order?

According to NetSuite Help Answer ID: 23563

Cancelled sales order is different from a closed sales order. While you can re-open a closed sales order, you cannot restore a cancelled sales order. The ability to restore a cancelled sales order is covered by Enhancement 28338 - Allow cancelled Sales Orders to be restored (un-cancelled).

When a sales order has been cancelled, the only option is to re-create the order or make a copy of the sales order.

cheers @jcribb 🙂