With a bit more trial and error, I found the binaries in the Fedora 10 packageworked fine.
I think I found the issue though, with the OpenWRT binary.
BC seems to be comprised of two binaries.. one called “bc” the other called “dc”. It would seem bc calls dc internally (probably the cause of the “No such file or directory” error seen earlier.
With the OpenWRT package, bc and dc are packaged separately (I only installed bc). However the fedora package includes both binaries by default, which prompted me to copy both across. Then it worked fine!
Thought I’d post the solution here, just in case anybody else needs this.