When I was moving recently, I came across the bolos I made out of old rat tail tang cheap swords, including the one mentioned in this thread. I removed the tang entirely then ground the first few inches of the blade into a new handle using a grinding wheel, then wrapped the handle and sharpened them up as much as I was able (crappy steel prevents too much). So, the swords are now full tang. Not good steel, not good geometry, but they're fine for chopping through vegetation. Sawed the sheaths a little shorter and rewrapped. The blades are now short enough that I'm not too worried about them breaking through vibration or impact.
The other one was from a yari, btw.
Its nice to have a sword or two that are cheap but sturdy, that you're not afraid to damage or abuse. Better than throwing them out, I'd say.
That's pretty much the spirit of the bolo anyway, as I understand it. My instructor has one that he got in the PI made from an old car door.