So I got this IBM Model M that has a part number 1397661. It is a blue label and is made in 1992. It is PS/2, buckling spring, has drainage channels, and only has 1 piece key caps. So far I can't find any information on it beyond this item for sale at Clickykeyboards stating that it is identical to the 1391409. But theirs says it has 2-piece keycaps.
http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/9229/subcatid/0/id/132172
Any ideas?
There's a huge number of random part numbers associated with any piece of IBM hardware, and nobody bothers keeping track of them all, preferring to focus on common and distinct PNs.
From the sound of it, your keyboard is a 1391401-style keyboard with one part keycaps. AFAIK, you could request in your order with IBM whether you wanted a keyboard with one or two part caps, there are certain situations where the one part caps would be desirable, for example - a school or library where the two part caps may encourage people to steal bits.
