I don't know if this wil help, but I found this:
Q: What is a Linker?
A: There are two kinds of products known as linkers.
One is a stand-alone machine that has a round cylinder of needles that a piece of knitting will be hung on. The second piece of knitting is hung over the first and the linking machine will seam the fabric together.
The other type of linker is a small carriage-type accessory that "walks" across the knitting machine bed. This linker provides a quick, neat cast-off edge, or it can be used to join two pieces of knitting.
From this site: http://home.earthlink.net/~rhfarm/id14.html
It seems this site is in the UK, and they have all sorts of info about knitting machines, even old ones that are n't being manufactured! Hop this helps!