The sink in mine is molded by Winnebago. Close to the left back corner there is an extension to make it easy to remove the sink cover that covers half of the sink to provide additional work area.
I wanted to replace it with a stainless steel one and did a lot of looking but could find nothing that would fit even if I covered the extension area somehow.
While at the factory I checked to see if they had a stainless steel sink that would fit but they didn't.
On the positive side, the plastic one has lasted for 11 full timing years and one snowbird year. I did have to use Soft scrub with bleach or the Clorox cleaning spray with bleach to remove stains.
Clay WA5NMR - Ex Snowbird - 1 year, Ex Full timer for 11 years - 2004 Winnebago Sightseer 35N Workhorse chassis. Honda Accord toad.