Lexmark NEW Computer Keyboard Model M C3229A PN1428260Lexmark-branded M-102s are rare enough. This is only the 2nd time I've seen 122s for sale—and these are NIB, so they seemed worth bringing to your attention.
And because these are later-model terminal
emulation boards, not plain terminal boards, they're PS/2 and can be used directly with modern PCs (straight to PS/2 or with an active USB converter).
In case you have trouble reading the listing (only the left half of it is appearing here in Chrome, so I had to Select All and paste it into an editor), here's the crucial line:
"Model M buckling spring keyboard new in original box with assorted new cables and 4 pin mini-din male connector."
The AC cables that were bundled with this board indicate it was part of a system package. (I have yet to see a keyboard that requires one.)