Yale lever door lock... part fell out, where does it go?

[Emy]

This was supposed to be a simple thing... the instructions show 4 parts, but this little thing fell out of somewhere and my husband doesn't remember where. Probably the interior side. Does anyone know?

 

[big-all]

ok the bit on the key lock that looks like a lolly stick that bit sits on the back off the bit above the cup that clips or sits on the face looking at the key lock
so in short place the cup on the bit above with the open face towards the actual key lock