imageCLASS mf462dw can't figure out how to reattach plastic piece in back panel

[sbonfigli]

I had a paper jam in my imageCLASS mf462dw. The paper was crunched behind the back panel. There was a plastic piece that was running the width of the paper and it came free as I tugged on the crumpled paper. There is a similar piece that was above it that is still attached. I cannot figure out how to reattach. The piece is about 1-1/2" tall with lots of points sticking out on both the top and bottom edges across the length which is about 9-1/2" across. On each end, there is a single nub that looks like they would sit in holes and then allow this piece to flap as paper comes through. I just can't find any little holes to insert this into. One nub is shorter than the other. However, it doesn't appear that either is cut short -- they appear as finished nubs. 
The back cover does not appear to come off and it just tilts open which doesn't give me a lot of access. I tried lifting the similar flap above thinking that the flap no longer attached previously attached somewhere underneath. But there's hardly room to get my fingers in with the back panel only opening at a tilt. 

Anyone know where this plastic piece is supposed to attach under the back panel?

piece goes under back cover

[sbonfigli · Accepted solution]

Resolved! The plastic piece actually connected by the nubs to the drop down back door, not inside the printer. Double-sided printing is working.