From Newsgroup: comp.sys.ibm.ps2.hardware

http://ps-2.kev009.com/ohland/Tape/ITBU_Installation_Kit.html

I think the black plastic mounting clip is also called the stop clip.

"Mounting Clip for Model 40 / 57 / 77 [black plastic]
92F3762 Stop Clip Bay 3 of 8557, 9557, 9577 and Bay 2 of 9556 and 9576"

That's it for now...
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