Very precise analysis.
I've replaced 15 or 20 0f those rear cassette guides, usually schools. You'll get an enduser that decides they'll bowling for a strike, with a full ream of paper. The impact busts the rear guide.
You'll also find that some endusers lean on the tray, and break holes in the bottom front of the cassette rails. The symptom is that the tray stops 2" shy of latching. If you lift the tray a little it will close.
=^..^=
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