Thank you for all the time and effort you've gone to in order to get this scanned and uploaded, it's a shame Alps seems to maintain an antagonistic relationship with the keyboard community.
Some observations on a quick scan-through
1) This catalogue seems to use the spelling 'ALPS' fairly consistently in technical tables, but uses 'Alps' on page 2 for example.
2) Official confirmation that their switch naming makes little sense - `SK` is confirmed to be Single Key, but the next two letters in every switch type (in the entire catalogue, not just the SKCM/SKCL switches) are always claimed to describe "Contact structure and variety", and the next two letters are always "additional mechanism and variety". If CL/CM or the following two letters mean anything in English/Japanese, it remains a mystery as to what it is.
3) SKCL yellow are 60g in weighting, which seems surprisingly light, I thought they were heavier.
4) The catalogue classifies into only two types - ones with a "click feel" (SKCM), and ones with a "soft feel" (SKCL). They do not group switches into clicky/tactile/linear like we do in modern times, instead putting tactile/clicky together in one category, then further describing if there is a "tactile sound" (or just "quiet" in the case of damped cream, née Ivory).
5) SKCMAT (Neon Greens) are listed as peers alongside the much, much more common Black/White/Cream Damped, I wonder why they are so rare? Did customers not like their force curve? Were they more expensive? Did they have production issues? Did the planets simply not align and everyone chose black over them?
6) SKFS also appear, the Apple Adjustable keyboard was released in 1993. It's described as "click feel", so the Deskthority wiki describing them as clicky was probably misinterpreting the source catalogues division of click feel/smooth feel. I have an example and can confirm it's not 'clicky' in the modern sense of the word.
7) Ladies and Gentlemen - the Alps AX Keyboard, aka Alps Bigfoot is confirmed as an off the shelf Alps keyboard (although this was already pretty much the conclusion). Minimum order of 100 units! Reckon we could get a group buy going? KF (for full keyboard), CL/CM (matches the SKCM/SKCL switches that are used) and then the rest consists of Alps' indecipherable code that contains "product structure and variety" and "Alps control number". On page 14 the catalogue describes AX as being the abbreviation of "The Architecture Extended", which is an extension of PC/AT that can support both English and Japanese.
All in all, I think the community had worked out most of the information here, but it's good to have confirmation. I hope one day we get our hands on earlier catalogues, it would be great to see if orange/salmon/black all appear in a 1990 catalogue for example, and how they're differentiated.
