So, you have an RK05 drive, but you're missing the slides to mount it? Your troubles are over (sort of :-).
It turns out the slide DEC used was the General Devices 'Chassis Trak' C-230-S-122 (22") - and those are still available (e.g. from Newark). They're somewhat pricey - the -124 (24") is slightly cheaper, and can easily be modified to fit an H960, viz: http://ana-3.lcs.mit.edu/~jnc/tech/jpg/24InchSlide.jpg The one in the image actually came off an -11/05 in a 10-1/2" box; the 3-3/8" outer slide pair from the RK05 slides does in fact fit the inner slides (i.e. the part permanently fixed to the box) used on a lot of BA11 boxes. One hitch: the location of the safety latches (the 'buttons' on the inner slides that pop out through holes in the intermediate slides) is different on most of the BA11-K inners (on the three BA11-F's I've looked at, they do match), and so the latches don't work. (Unless of course you make the correct hole in the intermediates, or drill new holes in the inners that come with the slide set, to match the mounting holes on the BA11-K, and use them instead.) So, better than nothing, if you have BA11's (or similar) and don't have the outer slides, to mount them. Noel