Where can I find the core binaries for v.0.1.5 to v.0.3.21? I have been looking for core binaries (i.e. win32-setup.exe &amp; win32.zip &amp; macosx.zip) for earlier clients. Any advice on where they are hosted? They have all been removed from SourceForge.

https://satoshi.nakamotoinstitute.org/code/ (Only v.0.1.0 to v.0.1.3)
https://bitcoin.org/en/version-history (Only v.0.3.21 to v.0.20.0)
https://github.com/bitcoin/bitcoin/releases (Only tar.gz, also not accurate)

Any advice appreciated!
You have the files here and can follow the instructions mentioned in below links to build:
https://github.com/bitcoin/bitcoin/blob/master/doc/build-windows.md
https://github.com/bitcoin/bitcoin/blob/master/doc/build-osx.md