WooCommerce: Marking a product as SOLD

Does anyone know of a way to keep a product in the store, but mark it as being “SOLD”?

I have managed to get it to work to a fashion using the Sold Out Products plugin, but it means changing the status of the product to “Out of stock”, which is not ideal.

Any other suggestions gratefully received.

http://wordpress.org/extend/plugins/woocommerce/