Apologies for the necro post, but was looking for pics of one of these, and was happy to see some detailed ones here
The LK-series keyboards are associated with the OpenVMS operating system, and Digital's LK-series terminals. There are many software packages out there (and in-house software) which depends on that layout. There are emulators which approximate the layout on a standard PC layout, but some people put a premium on the orignal layout, and thus those keyboards command a high price. These later models are also the only ones which are USB-native (as opposed to PS/2, or the older DEC proprietary interface which used a connector which looks like an RJ11 jack).
The older ones (made by Honeywell) had dye-sublimated PBT keycaps, and the rubber domes they used are quite firm and responsive when they are new or in good condition (well worn ones feel pretty junky, like most rubber dome keyboards). It seems like the newer ones (which were made by Cherry) are lower quality. The legends, keycap profile and case on the Cherry ones are pretty much identical to the Honeywell ones, and have pretty much nothing in common with Cherry's other keyboards, which makes me suspect that Cherry acquired the tooling from Honeywell at some point and made them under contract for HP.
