This Things of Science unit covers some of the same ground as the Straight Line unit but goes into even more in depth. In addition to Watt’s Linkage, the Peaucellier Cell and the Cissoid Curve, this unit adds pantographs and angle trisection linkages.
This kit may be more or less complete (as purchased from eBay). From the photo above you can see the extensive linkages that were included. Lengths for the linkage bars are given in the booklet, so you can easily (and inexpensively) duplicate this kit.