You can buy an L3961 kit. I bought one from my dealer for just over $500. I haven't had it on yet, but it should fit. It's listed for L39, 45, and 47, not the L35 since our L35's came with it and it was optional on the later models.
I've been meaning to post pictures and dimensions, but haven't got a round tuit. Here's a few pictures. You get everything in the diagram, including the top link, bolts, etc.
View attachment 63350
View attachment 63351
You get a few parts you won't need on an L35, since they're already installed.
View attachment 63350
View attachment 63351
View attachment 63350
View attachment 63351