Yes, those retainer clips are pretty fragile! You should be able to pick up a replacement taillight/lens assembly at any RV parts center. I also replaced the power cord "hatch" on our TM. That part was available at the locale RV parts center.
Here is a link to a dealer near us:
http://www.rvlifestyles.net/Order.as...X0710140040887
Click on "Electrical" (left side of window); scroll down and click on "taillights"; click on "more info" for #92 Series Surface Mount Taillights which brings up a page with several taillight choices. They don't show a picture of the license plate bracket but it is listed in the description.
Go back to the "Electrical" page and click on 'Hatches"; go to page 2 to see the listing for the power cord cover.