[B8bydesign]

The guys at Eurowise should be able to help you out, especially since you're already familiar with them and they know the car. I recently had an alignment performed there and they had to drop my Varis Undertray in the rear and noted I was missing some screws/bolts and even gave me a few different sizes as example so I could pick some up at the hardware store.

I know you said you want to keep the car stock, but I can't recommend going with an aftermarket skid enough, especially with these roads, you'll be buying new OEM felt pieces every couple months (unless you rarely drive your car).