I want to use Armory's Python library for running a watch-only wallet on a machine unable to store the entire blockchain.
I'm not sure how you'd go about implementing a watch-only wallet using Armory without having the entire blockchain. Armory is designed to require it. If you want some Python software to implement a watch-only wallet, something Electrum-based might fit your needs better.
After running make on the Armory Github source, which files are required to import armoryengine.ALL?
FYI you don't need to build Armory from source in order to use its libraries, you can just use one of the distributed packages (unless of course your target platform isn't among those supported).
I know that doesn't answer your question, though.... sorry I don't know the answer, but my guess would be most of the .py and .pyd files except the BitTornado stuff, although I really don't know the details.