Alps SKCR Series
Alps SKCR is a mechanical switch series yet to be formally identified. The series name is known only from an eBay listing for an IBM 5576-002 keyboard, whose box bears the Alps model number KFCREA087A (IBM part 07G1451). The switches are not revealed, but only two switch types are known from 5576-001 and 5576-002: SKCP plate-mount “plate spring” switches, and the square-shell PCB-mount “plate spring” switches.
It seems reasonably likely that SKCR series represents the square PCB-mount equivalent of KCP/SKCP. However, this will not be confirmed until a 5576-001 or 5576-002 keyboard with its original box has its switch type revealed.
The IBM P70 and P75 keyboards used a different style of PCB-mount “plate spring” switches, and these could be SKCQ, SKCR or another series.