Hey JB,
Sorry for the late reply. I removed the main landing gear doors from my plane and will perhaps reinstall later as I become more familiar with this airframe. Skymaster sent me carbon fiber cloth to reinforce the main gear doors. It was my understanding that everyone with the PC-21 would automatically receive the materials for this purpose. You might email John, or Anton to find out when you might get what is needed.

For the landing gear struts, you should have received a kit containing a syringe, a short piece of tubing and a small air tank (you need to purchase the oil from your local hobby store as it was not included with the plane). The purpose of the syringe and tubing is to allow you to inject a silicone oil into the struts. The air tank is filled with compressed air which is used to pressurize the struts. If you go to the Skymaster website you will find a video tutorial in the instruction manual section that shows how to properly prepare the retract struts for use.

The silicone oil that I used in my retract struts was purchased from the local hobby store. It is GS Racing (GSC-70028) Pure Silicone diff. Oil 10000cps.

Send me a PM with your email address, and I will send you pictures of my equipment installation. Let me know if you need any addition information.