Broke down and ordered the original legs. Cost almost as much to ship as to buy, but whatever, I'm a nerd like that.
Kinda interesting sidenote. in the pile o' parts is a Jacobs model 4364 chuck on a Craftsman 1MT/threaded adapter. The chuck is the type you would expect to see on an old hand drill in which the threaded axle presses on the plate which in turn draws the jaws out to clamp on the bit- in fact the only reference to this chick I was able to find with the Google was from a guy who was restoring a hand drill with one, and he could find nor references to this chuck other than it's patent date (1944) and it's replacement patent (1949). The 'C' in Craftsman on the shaft is the earlier 1930's style chiseled Fred Flintstone script, so while certainly no proof, I'm leaning towards calling this little guy a 1944. In the 1948 Craftsman catalog the chuck is listed as a "Jacobs Hand Tite".