Funny you should bring this up.
I'm a big fan of RockAuto. It's a local company from my home state.

I broke the tether on my gascap recently. Found 4 items at RockAuto and picked Gates. All 4 were +/-$3.

It came yesterday. It is a bagged original OEM Mercedes Benz part. In the correct P/N Gates box.

Imagine my surprise!

And OEM M/B was not one of the options.