At your yard sale I'd put the 127 up for $20.00 and the 66 for $10.00. They might or might not sell but that's a good starting point.
The 127 is really nice, the decals are far nicer than those on my example. The 66 looks good too, but it would take a good cleaning to see for sure.
Neither machine is too far gone to be refurbished and used. Both machines are electric motor or hand crank compatible, and they are standard size machines so cases are available.
All that's needed is a treadle cabinet or a case and some ambition. Well ....... a bit of money too, I guess.
Joe