I know you mentioned Craigslist, but that's my go-to place when looking for old bikes and parts. CL has "bikes" and "bike parts" sections...be sure to check both since people will post random stuff to both. Yeah, prices have gone up because people hear how everyone wants bikes now so they suddenly think their old bike is worth more than gold but there are some decent priced finds out there too.

Congratulations on the recently finished Super Course conversion...sounds like a fun bike to ride.