The Mueller bridges (branded ABM) are the beginning and end of specifically headless bridges. Either a three-piece unit (headpiece, tailpiece and bridge), or a 7-piece (headpiece and six individual saddles/bridge pieces). All machined from (mostly) steel by German engineers. What more do you need?
www.abm-mueller.com/headless_units.html
b) What are the ingenious practical ways that one could make a headless bridge?
Be an engineer. ? Look at the ABMs or the original Steinbergers - it's not a complex design, but they are precision made fromm good materials.
If you haven't already found it, Building the ergonomic guitar is a priceless resource:
http://buildingtheergonomicguitar.com/2006/09/headless-guitar-resources-for-guitar.html