Gold Star Alps
Two of the rarest Alps switches are SKCL Brown and SKCL Amber. These were found side-by-side in a Packard Bell KCLEA907L keyboard manufactured by Gold Star Alps in Korea. The PCB code is 12KC619BK, with a final “K”.
A similar keyboard, BIOS Express KCME907L, was also made by Gold Star Alps in Korea, with the same PCB code; this has SKCM Blue switches.
It is interesting to note that another example of SKCL Brown occurs in an unidentified Visual Technology keyboard; here, the PCB code is 12KCA10AK.
My theory is that the final “K” in the PCB code stands for “Korea” and indicates that the keyboard to which it belongs was made by Gold Star Alps, and that for whatever reason, Gold Star Alps SKCL switches were a different colour to Japanese SKCL switches. Whether this is because they had different pigmentation available, or because the switches were specified differently, remains a mystery, as no force curves are known to exist for these switches.
Interestingly, the latching switch colour follows that of the normal key switch (brown), instead of the space bar switch (amber), as seen in some unidentified keyboard, of which nothing else is known at the time of writing, except that the serial number ends in “K”.